Electrical 92 GT Convertible - Fuse 13 Continuity Testing Question

Mrg2783

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Apr 1, 2018
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Hey there,

I have no interior dash lights, except the radio works and dome light and the exteriors are all good.

Tried two dimmers, turned all the way down, fuse is good. Once I turn them up, no lights, hits "Dome Light on" and pops the fuse.

So read I have to test the LB/R wire per the schematic.

This is a first for me so go easy haha

In the pictures below I tapped into the LB/R striped wire and connected it to my battery powered continuity tester, grounded the continuity tester and it lit up.

I did have the battery disconnected.

Did I do this correctly and if so, this means I have a short correct?

I did the same thing on the connectors for the cluster, for the dimmer switch.

They all lit up... If I have a short, they would all trigger as they look like they're all connected on the same line.

But I'm just stumped on how to pinpoint where this is coming from exactly in regards to isolating and eliminating each instrument.

Could it be the LCD illumination relay? Where is that located? I'm not sure where to start on that part.
 

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Blown88GT

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At least you have the EVTM. it would be impossible to find without it.

Yes, you have a partial short. All the dimmer is doing is reducing the voltage & therefore the current.
A partial short is not 0 ohms, but something above, maybe 10 ohms.
Could be the LCD Illumination Relay (I have Day/Night Illumination Relay), but I doubt it.
Nothing in there that would cause a partial short unless it got filled with water.
If not that, the I'm going to guess the radio, removing connector C-257 will isolate it.
My radio doesn't use Fuse 13. Never knew there was differences there.
Could also be just a little bit of corrosion in one of the illumination lamps.

Continuity tester won't cut it any more. You need a multi-meter, even a Harbor Freight cheap one is free with any purchase.
You need something to measure Ohms. Ohms scale uses an internal 9V battery. Measure from S-208 side of fuse (with fuse removed) to good body ground near where you're working. The green colored screws are the best.

Because all the lamps are in the circuit, you will get 100's or 1000's ohms because they are all in parallel. To blow a 5A fuse, you need 2.4 ohms or less. If the dimmer was supplying 5V, you need 1 ohm or less to blow the fuse. I would estimate the normal load on that circuit is 1-2 amps, it's just a bunch of lamps at 1/4 A each.
This indicates you will need to be able to measure 1-2 ohms. You don't actually have to measure that low, only have to see it go from very low to high on the 200 ohm scale, when you remove C-257 or whatever load is the culprit.

If it's within you budget, get an auto ranging multi-meter. It will make all electrical tests easier now & in the future. You don't need a $400 Fluke 87 like mine. I use it for everything, auto & home, but I am a professional (LOL).

V=I * R
Volts = amps * ohms
12 = 5 * R
R = 2.4
 
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Mrg2783

Member
Apr 1, 2018
81
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Newport Beach
At least you have the EVTM. it would be impossible to find without i

Yes, you have a partial short. All the dimmer is doing is reducing the voltage & therefore the current.
A partial short is not 0 ohms, but something above, maybe 10 ohms.
Could be the LCD Illumination Relay (I have Day/Night Illumination Relay), but I doubt it.
Nothing in there that would cause a partial short unless it got filled with water.
If not that, the I'm going to guess the radio, removing connector C-257 will isolate it.
My radio doesn't use Fuse 13. Never knew there was differences there.
Could also be just a little bit of corrosion in one of the illumination lamps.

Continuity tester won't cut it any more. You need a multi-meter, even a Harbor Freight cheap one is free with any purchase.
You need something to measure Ohms. Ohms scale uses an internal 9V battery. Measure from S-208 side of fuse (with fuse removed) to good body ground near where you're working. The green colored screws are the best.

Because all the lamps are in the circuit, you will get 100's or 1000's ohms because they are all in parallel. To blow a 5A fuse, you need 2.4 ohms or less. If the dimmer was supplying 5V, you need 1 ohm or less to blow the fuse. I would estimate the normal load on that circuit is 1-2 amps, it's just a bunch of lamps at 1/4 A each.
This indicates you will need to be able to measure 1-2 ohms. You don't actually have to measure that low, only have to see it go from very low to high on the 200 ohm scale, when you remove C-257 or whatever load is the culprit.

If it's within you budget, get an auto ranging multi-meter. It will make all electrical tests easier now & in the future. You don't need a $400 Fluke 87 like mine. I use it for everything, auto & home, but I am a professional (LOL).

V=I * R
Volts = amps * ohms
12 = 5 * R
R = 2.4
I friggin love this site... haha... Thank you so much!

Looks like s208 references in harness C251. That is the circled harness, correct?

I have a basic meter, for now, will this do the job?

And should the positive lead be plugged into fused or unfused on the meter? Assuming unfused?

Now as a side note,

I bought a 5 amp breaker fuse, popped it like 20 times just trying to move play touch everything, and for some reason all of a sudden the dash lights came on after I put the radio away and climate control cluster panel. Confirmed there are no open wires. Mirrors work fine nothing showing as far bad wiring, like nada visually, opening wrapped wires, all of it.

so after I put everything away all of a sudden im playing with the dimmer and it works. Switched the old dimmer that worked now with a new one I had and it worked with a new dimmer as well. Two good dimmers.

I put everything back together. Turn the lights on, still works, but I notice the main head light switch lighting is considerably dim now compared to the other hazard/Convertible Top switch.

Now about 5 minutes later, POP. Fuse 13 blows, for no reason. I didn't even start the car I didn't move anything I was literally just sitting there, outside of the car, looking at the lights and pop. Also this time a twist, for the first time it blew Fuse 4 for the parking lights.

Now the dimmer flicks one bulb on in the dash when set to "Dome on", no dome light, and it blows the breaker fuse after 2 seconds haha.

So no dash lights again, at random And NOW it stopped popping the fuse with the one dash light... Dimmer is dead, fuse doesnt pop, nothing is ground out now I guess?

mirror, radio, etc all have power. Fuse 4 is good still with all exterior lights working.

I bought a new head light switch for$27. Worth a shot I think at this point.

You ever come across this scenario? Read Fuse 4 is parking switch problems. Could it also mess with the dash?

Thanks!
 

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Blown88GT

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Your killin' me with questions.
If I had the car in front of me, I could narrow it down.
Stop throwing new parts at it, you will never, ever find the problem that way.
You need to be methodical & not jump all over the place.
I have never seen this specific problem before but I have seen partial shorts in a corroded lamp socket.
I even have one now myself with the underhood light. Under certain circumstances (hood closed, engine running), it will sometimes blow the fuse. I have been unable to find the cause, so I just unplug it. It's something to do with the LED replacement.

Let's deal with the meter. Fused & unfused is only if measuring amps, which you could do, but already know it's blowing fuses & popping breaker. Red lead goes to V..., Black lead goes to Com. To measure Amps or millamps, you have to place the leads in series, like across the fuse socket (with no fuse) so current runs through the meter. There is a fuse inside the meter to protect it from blowing. DO NOT DO THIS.

I can't identify the harness for you. That's something you have to verify. You have the EVTM, you will have to learn how to read all the info, it shows the wire colors & wire numbers. It is NOT a physical representation it is an electrical representation.

You have stated a very good clue, but didn't understand what it meant:

I bought a 5 amp breaker fuse, popped it like 20 times just trying to move play touch everything, and for some reason all of a sudden the dash lights came on after I put the radio away and climate control cluster panel. Confirmed there are no open wires. Mirrors work fine nothing showing as far bad wiring, like nada visually, opening wrapped wires, all of it.

Good job for getting the breaker fuse.
I believe the short could be inside the radio or in the harness to it. Maybe some insulation got scraped off on the harness, it touches the chassis & blows the fuse.
If not the radio or it's harness, it's some missing insulation on another wire.

You're not looking for an open wire, an open wire can't blow a fuse because it is OPEN.
Connect everything up, except for the radio.

Main Light Switch - this got me thinking, it only affects GT's. I remember seeing mine. The backshell of the main light switch was melted from the power feed wire. There was a TSB on this one. Don't know if it affected 92's, but they never did put a relay in there; can't tell if they upgraded the power feed to 12AWG.
---------------------------------------------------------------------------
In the February, 1991 edition of Popular Mechanics, the "Car Clinic" by Mike Allen had the following:
Fogged Out
"I have a 1988 Ford Mustang GT. After about 20 minutes with my headlights and fog lights on at the same time, the headlights blink intermittently."
Victor Alberico
Watertown, MA
"I rarely find the answer to a Car Clinic problem covered in a TSB, but every now and then...
Ford TSB 89-17-11 says this is caused by overheating in the headlamp circuit. It's a phenomenon affecting '83-'89 Escorts, '83-'87 EXPs and '87-'88 Mustangs. You'll need to replace the headlamp and dimmer switches, several connectors, and then bypass the wiring in the circuit with new 12ga wire run alongside the original harness. It's supposed to take 1.3 hours for a service technician to do this, and you ought to see if the dealer will still do the repair under warranty."
---------------------------------------------------------------------------
They wouldn't repair mine under warranty, but agreed to do it for $50. This was in 1991, $50 is like $150 now.
Look at the old Main Light Switch & the connector & wires to it. See if there's any evidence of melting or discoloration.
---------------------------------------------------------------------------
I recently changed this circuit so the fog lamp circuit is independent of the main lamp switch, no rewiring of any kind is required.
I was helping someone like you & all of a sudden it just came to me how simple this would be. Only an add-a fuse plugged in the right way in the fuse box. I then added DRL's to the circuit because the LED fog lamp bulbs were not very bright.

There is a recent YouTube video but the guy didn't understand when I tried to explain to him that the orientation of the add-a fuse is important. Otherwise, you have one fuse feeding another & then to the load. His fuse box was all messed up, mounted upside down, looked all wrong. He blew me off in not a very nice way. My 2 degrees in electrical engineering & 30 years experience did not impress him. I'm not looking to impress anyone, just don't disrespect me.

I did the cutouts years ago for cooling. GT's had reduced cooling, all airflow to radiator comes from under the nose. That's why '93 Cobras had a different grille.

IMG_0751.JPG

s-l1600-1.jpg
 
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Mrg2783

Member
Apr 1, 2018
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Your killin' me with questions.
If I had the car in front of me, I could narrow it down.
Stop throwing new parts at it, you will never, ever find the problem that way.
You need to be methodical & not jump all over the place.
I have never seen this specific problem before but I have seen partial shorts in a corroded lamp socket.
I even have one now myself with the underhood light. Under certain circumstances (hood closed, engine running), it will sometimes blow the fuse. I have been unable to find the cause, so I just unplug it. It's something to do with the LED replacement.

Let's deal with the meter. Fused & unfused is only if measuring amps, which you could do, but already know it's blowing fuses & popping breaker. Red lead goes to V..., Black lead goes to Com. To measure Amps or millamps, you have to place the leads in series, like across the fuse socket (with no fuse) so current runs through the meter. There is a fuse inside the meter to protect it from blowing. DO NOT DO THIS.

I can't identify the harness for you. That's something you have to verify. You have the EVTM, you will have to learn how to read all the info, it shows the wire colors & wire numbers. It is NOT a physical representation it is an electrical representation.

You have stated a very good clue, but didn't understand what it meant:

I bought a 5 amp breaker fuse, popped it like 20 times just trying to move play touch everything, and for some reason all of a sudden the dash lights came on after I put the radio away and climate control cluster panel. Confirmed there are no open wires. Mirrors work fine nothing showing as far bad wiring, like nada visually, opening wrapped wires, all of it.

Good job for getting the breaker fuse.
I believe the short is inside the radio or in the harness to it. Maybe some insulation got scraped off on the harness, it touches the chassis & blows the fuse.
If not the radio or it's harness, it's some missing insulation on another wire.


You're not looking for an open wire, an open wire can't blow a fuse because it is OPEN.
Connect everything up, except for the radio.

Main Light Switch - that got me thinking, it only affects GT's
There was a TSB on this one. Don't know if it affected 92's, but they never did put a relay in there.
---------------------------------------------------------------------------
In the February, 1991 edition of Popular Mechanics, the "Car Clinic" by Mike Allen had the following:
Fogged Out
"I have a 1988 Ford Mustang GT. After about 20 minutes with my headlights and fog lights on at the same time, the headlights blink intermittently."
Victor Alberico
Watertown, MA
"I rarely find the answer to a Car Clinic problem covered in a TSB, but every now and then...
Ford TSB 89-17-11 says this is caused by overheating in the headlamp circuit. It's a phenomenon affecting '83-'89 Escorts, '83-'87 EXPs and '87-'88 Mustangs. You'll need to replace the headlamp and dimmer switches, several connectors, and then bypass the wiring in the circuit with new 12ga wire run alongside the original harness. It's supposed to take 1.3 hours for a service technician to do this, and you ought to see if the dealer will still do the repair under warranty."

---------------------------------------------------------------------------
Look at the old Main Light Switch & the connector & wires to it. See if there's any evidence of melting or discoloration.
---------------------------------------------------------------------------
I recently changed this circuit so the fog lamp circuit is independent of the main lamp switch, no rewiring of any kind is required. Only an add-a fuse plugged in the right way in the fuse box. I then added DRL's to the circuit because the LED fog lamp bulbs were not very bright.

I did the cutouts years ago for cooling. GT's had reduced cooling, all airflow to radiator comes from under the nose. That's why '93 Cobras had a different grille.

IMG_0751.JPG

Im sorry, no more questions.

Thank you for the help. Thinking ill just blow it up at this point lol. I'm growing tired of this car.

In regards to the radio, I meant it was all put away, found nothing while it was out. Screwed it all back in. left it alone for a little.

Went over and played with the dimmer switch/ fuse and then boom, lights work. Didn't work with the radio out while I checked all the wires either.

but like I said, I was just sitting there outside of the car, after 5 minutes goes by and, POP, fuse blows.

Ill tap the correct s208 side of the fuse and try discconecting items to see if the ohms jump.

Thanks again for the help.
 

Blown88GT

Founding Member
Nov 13, 1999
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Now apology necessary. I'm old & impatient.
We're going to figure this damn thing out if it kills me.
I've been editing while you were responding.
Eyeball the old Main Light Switch & Connector, now.
No matter what you find, you may want to fix this.
They easy way is not to upgrade the wiring, just get the fog lamps out of the main lamp circuit.
Ford engineering didn't think of this for the TSB. Okay, I didn't either, but I'm now older & wiser (I hope).

It was a bad design. Every vehicle made has a relay for the headlamps but that would have cost an extra $1 * 1 million.
My only question is where was the chief engineer who signed off the design?
I know (he was a mechanical engineer & they don't know crap). I used to review the Mech drawings & have to fix their mistakes.

You really have that whole car torn apart. What's going on?
If mine ever gets that bad, it's going to junkyard heaven.
 
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Mrg2783

Member
Apr 1, 2018
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Now apology necessary. I'm old & impatient.
We're going to figure this damn thing out if it kills me.
I've been editing while you were responding.
Eyeball the old Main Light Switch & Connector, now.
No matter what you find, you may want to fix this.
They easy way is not to upgrade the wiring, just get the fog lamps out of the main lamp circuit.
Ford engineering didn't think of this for the TSB. Okay, I didn't either, but I'm now older & wiser (I hope).

It was a bad design. Every vehicle made has a relay for the headlamps but that would have cost an extra $1 * 1 million.
My only question is where was the chief engineer who signed off the design?
I know (he was a mechanical engineer & they don't know crap).

LOL I'm young and impatient so I can respect that 100%!!!!

You're nicer than I am going to be I'm sure lol

I do ask a lot of questions lol so thank you for taking the time.

Good thing is I wont ask the same question twice typcially :)

Im praying its the dang head light switch.

Im not the worst at this stuff but I just cant find the problem and my OCD makes me hate life haha

New switch comes in a couple days. The fact the head light switch lights were dimmer than the others gives me hope.

Plus its a vert, never had the top up more than 20 times, also garaged. The San Fernando Valley 100 degree heat and trips to Vegas have hit the headlight switch for all of its 49,000 original miles. So hopefully, with some luck, we will see what happens.
 

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Blown88GT

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I assume you haven't had it long?
Probably why the PO sold the car, got fed up with it.
Looks good in the pics. Never see verts here, any more.
It's so hot here in the summer, I don't even use it. 90-95 , 80% humidity.
When temps drop in Nov., it will come out on the 1st 80deg day.
Had a chance to move to your neck of the woods, Rockwell International (now Boeing), Santa Susanna, old Rocketdyne site.
They didn't want to pay enough to make the move worthwhile.

These electrical problems can be a major PIA. Had them at work, too. Never get used to it. Usually something simple.
It's a 26 year old car meant to last no more than 5. Be glad it only has 1 computer & that most of the other parts are still available in one form or another.

While you're waiting for the switch, get the add-a-circuit, either locally or eBay.
You're going to need this, too, if you still use the fogs.
 
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Mrg2783

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I assume you haven't had it long?
Probably why the PO sold the car, got fed up with it.
Looks good in the pics. Never see verts here, any more.
It's so hot here in the summer, I don't even use it. 90-95 , 80% humidity.
When temps drop in Nov., it will come out on the 1st 80deg day.
Had a chance to move to your neck of the woods, Rockwell International (now Boeing), Santa Susanna, old Rocketdyne site.
They didn't want to pay enough to make the move worthwhile.

These electrical problems can be a major PIA. Had them at work, too. Never get used to it. Usually something simple.
It's a 26 year old car meant to last no more than 5. Be glad it only has 1 computer & that most of the other parts are still available in one form or another.
I've had it actually since April of 2016. I purchased it from the Widow of my father's best friend who built it out in 1996.

The car has sentimental value. Picked me up in it when I was 14 years old over 20 years ago. Fell in love with it. Used to take me through Mulholland Hwy. Greatest times of my life.

I took this thing all the way down to the engine block decarboned the motor, Replaced every sensor, solenoid, 60lb injectors, new 3/8 inch fuel line and 340ml fuel pump ... literally the only thing I haven't replaced is the smog pump, starter, the steering pump or the master cylinder. I even sent the computer out for testing. I messed up when I did my head gaskets and lower intake the first time. I tore this thing down to the block twice God help me. Lol

I have to have over 200 hours in this thing plus an engagement lolol

I know these cars are never perfect but literally I'm so close LOL

I was about to do my warm up cool down start and recheck all my head bolts and then the lights go out so of course my OCD won't let me move forward until I fix the lights LOL

what's more annoying is that did a full LED conversion inside and out last year and everything has been working great ever since and then boom now this.

how much do entry-level Foxbody techs get for being a mechanic? LOL if I can make like 40 or 50 an hour I'd be set loving life. LOL

They charge $150 an hour out here for Foxbody Techs that know what they're doing. Hence why I did it all myself.


Here are the specs:


ENGINE
Balanced and Blue Printed
Ported and Polished
302- Now .036 Line Bored and Decked
VORTECH Super Charger “B” Trimmed
340 ML Fuel Pump
⅜ inch fuel line
COBRA Upper Intake
GT-40 Lower Intake
TFS Fly Cut Pistons
TOTAL SEAL Rings
SHOT PEENED Rods
1.6 COMP Roller Rockers
Custom Crank and Bearings
COMP Push Rods
COMP Timing Chain
COMP 294 Blower Cam
TFS Twisted Wedge Aluminum Heads/
“O” RINGED – 30 LB Boost Capability
EDELBROCK 70MM Throttle Body
SVO Harmonic Balancer
DYNAMAX 2 1/2” Exhaust
MSD Ignition System
Cardone Distributor & Rotor
EDELBROCK Maxfire 8.5MM Plug Wires
NGK V-Power Spark Plugs
FEL-PRO Gaskets
ALL ARP Bolts
60LB Ford Performance Fuel Injectors
BLOWER COMPRESSION - 8 ½ to 1
UPPER & LOWER PLENUM - Extrude Honed
SEALED High Capacity Oil Pump & Shaft
EDELBROCK Water Pump
PRO-M 80 Mass Air Sensor
B&M Oil Cooler
130 High Amp Alternator
Fender Well Air Induction System

SUSPENSION
BBK Strut Tower Brace
STEEDA Sub-frame Connectors
STEEDA Camber/Castor PLATES
STEEDA Boxed In Upper & Lower Control Arms
EIBACH Shocks & Struts
EIBACH Springs
FRONT & REAR Sway Bars
POLYURETHANE Bushings

ADDITIONAL MODIFICATIONS
McLeod Street Extreme Clutch
Adjustable Clutch Cable
Aluminium Quadrant
B&M Short Shifter
“BEAR CLAW” Racing Brakes
AUBURN Racing Rear End w/355 Gears
Aluminum 3 Channel Radiator
Electric Fan 180°
SALEEN Roll Bar
WHITE Gauges
LED Lights - Interior/Exterior
PROXES TR1 Tires (Front)
NITTO NT555R Compound Tires (Rear)
All new sensors, valves, and solenoids
Upgraded T-5 Transmission
 

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jrichker

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@Mrg2783

Troubleshooting tip: the (Cxxx symbol on the diagram indicates a connector. The first step is to reduce what you are testing to a bare minimum. Disconnect as many things as possible in the specific circuit you are testing and then do the testing. If it still trips the breaker or blows the fuse, the problem is in the remaining part of the circuit. If it doesn't trip the breaker or blow the fuse, then reconnect the disconnected connectors one at a time. When it causes the breaker to trip or the fuse to blow, you have found the offending part of the circuit.

See the video below for help finding short circuits.

View: https://www.youtube.com/watch?v=TZrCrBx4uFY

This is the tool that was used in the video.

View: https://www.amazon.com/Tool-Aid-25100-Short-Tester/dp/B000RFLR0U/ref=pd_sim_60_3?_encoding=UTF8&pd_rd_i=B000RFLR0U&pd_rd_r=A9S2NPZRPM1AFK2QF2MN&pd_rd_w=S1VUH&pd_rd_wg=9Rg28&psc=1&refRID=A9S2NPZRPM1AFK2QF2MN


If you decide that this is what you need, the following disclaimer applies. I don't have this device and haven't personally used it.
 
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Blown88GT

Founding Member
Nov 13, 1999
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Palm Beach Gardens, FL
You missed his picture. Wouldn't you agree "everything is disconnected"?
565335-744e48d80c644b7a2412209e960f13dd.jpg

He doesn't have an active short. It's an intermittent, partial (or low ohm) short.
Outlined in #1 post.
Explained in #2 post.

I watched the entire video. It's very good. I like the tools he used.
He's selling them for $40, probably buying on eBay & reselling for a nice profit.
The other tools he used are there, too.
http://www.realfixesrealfast.com/short-finder.html
I'm getting one, directly from eBay, save $6.50

---------------------------------------------------------------------------
While he's at it, here's the fog lamp fix to enable them to function independently of the headlights.
Add-a-circuit goes into #16 (20A-yellow), red pigtail connects to load (left) side of #15 (15A-blue).
Pigtail comes with a butt splice, cut it off & crimp a spade connector on.
#12 is pointing to the empty position below. #15 has an arrow pointing to the position above it.
#15 is only for the Fog Lamps & nothing else.

BTW, didn't have to use #16, but wanted something on the same 12V bus bar as the headlights (#4) or #8.
4, 8, 16 are fed from the same 12V bus, all fed by fuselink B.
The problems with 4 & 8 was clearance for the add-a-circuit & the fuse panel cover.
You can see that #4 is in the lower left corner. That was the perfect one until I tried to put the cover back on.
Actually, #16 is better because you can tell which fuse is which by the color.

Fog Lamp Circuit Fix.JPG
 
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Mrg2783

Member
Apr 1, 2018
81
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@Mrg2783

Troubleshooting tip: the (Cxxx symbol on the diagram indicates a connector. The first step is to reduce what you are testing to a bare minimum. Disconnect as many things as possible in the specific circuit you are testing and then do the testing. If it still trips the breaker or blows the fuse, the problem is in the remaining part of the circuit. If it doesn't trip the breaker or blow the fuse, then reconnect the disconnected connectors one at a time. When it causes the breaker to trip or the fuse to blow, you have found the offending part of the circuit.

See the video below for help finding short circuits.

View: https://www.youtube.com/watch?v=TZrCrBx4uFY

This is the tool that was used in the video.

View: https://www.amazon.com/Tool-Aid-25100-Short-Tester/dp/B000RFLR0U/ref=pd_sim_60_3?_encoding=UTF8&pd_rd_i=B000RFLR0U&pd_rd_r=A9S2NPZRPM1AFK2QF2MN&pd_rd_w=S1VUH&pd_rd_wg=9Rg28&psc=1&refRID=A9S2NPZRPM1AFK2QF2MN


If you decide that this is what you need, the following disclaimer applies. I don't have this device and haven't personally used it.

Awesome. Thank you for the input. Since it is put together now, I'm going to pray its the headlight switch. Doubt it. But worth a shot before I pull her apart for the 6th time haha.

Thanks for all the help. I will keep you guys posted on what happens!
 

jrichker

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Mar 10, 2000
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You missed his picture. Wouldn't you agree "everything is disconnected"?
565335-744e48d80c644b7a2412209e960f13dd.jpg

He doesn't have an active short. It's an intermittent, partial (or low ohm) short.
Outlined in #1 post.
Explained in #2 post.

I watched the entire video. It's very good. I like the tools he used.
He's selling them for $40, probably buying on eBay & reselling for a nice profit.
The other tools he used are there, too.
http://www.realfixesrealfast.com/short-finder.html
I'm getting one, directly from eBay, save $6.50

---------------------------------------------------------------------------
While he's at it, here's the fog lamp fix to enable them to function independently of the headlights.
Add-a-circuit goes into #16 (20A-yellow), red pigtail connects to load (left) side of #15 (15A-blue).
Pigtail comes with a butt splice, cut it off & crimp a spade connector on.
#12 is pointing to the empty position below. #15 has an arrow pointing to the position above it.
#15 is only for the Fog Lamps & nothing else.

BTW, didn't have to use #16, but wanted something on the same 12V bus bar as the headlights (#4) or #8.
4, 8, 16 are fed from the same 12V bus, all fed by fuselink B.
The problems with 4 & 8 was clearance for the add-a-circuit & the fuse panel cover.
You can that #4 is in the lower left corner. That was the perfect one until I tried to put the cover back on.
Actually, #16 is better because you can tell which fuse is which by the color.

Fog Lamp Circuit Fix.JPG
After looking at the diagram, I have to conclude that not all of the dimmer controlled lights are in the instrument cluster. There are the heater/AC controls, radio illumination relay and the ashtray. The radio illumination can be discounted if the radio is disconnected.

The user has a full short circuit when full power is applied to the lighting circuit; the dimmer serves to limit the current until the brightness is turned up all the way to maximum illumination. The short may be intermittent, and it may require the wiggle and jiggle mode of testing.
 
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Mrg2783

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After looking at the diagram, I have to conclude that not all of the dimmer controlled lights are in the instrument cluster. There are the heater/AC controls, radio illumination relay and the ashtray. The radio illumination can be discounted if the radio is disconnected.

The user has a full short circuit when full power is applied to the lighting circuit; the dimmer serves to limit the current until the brightness is turned up all the way to maximum illumination. The short may be intermittent, and it may require the wiggle and jiggle mode of testing.
Thank you Blown88 for the fog light hook up information! Getting it done now so I dont have to deal with it later.Work smart not hard right?

And thank you Jrichker on the insight with the radio/ashtray illumination. Saves me from ripping apart the console again lol

Thank god, one less thing.

Ill tell you, I wiggled the S#$T out of every wire, on every harness and I could not get the lights to fire at all. Its the oddest thing.

I should have the new head light switch end of this week. I'm going to pray for 15 minutes each night for a miracle with the switch haha.

I highly doubt it since I had the meter light up at the LB/R wire coming out of the head light switch while it was disconnected, but one can hope.

Then, of course, ill be tearing into her again if all else fails.
 

Blown88GT

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What does the current (old) switch & plug look like? You can tell by looking at it if it was overheating. The switch is not only a switch but a thermal circuit breaker.
 

Mrg2783

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What does the current (old) switch & plug look like? You can tell by looking at it if it was overheating. The switch is not only a switch but a thermal circuit breaker.
I did look at the head light switch harness and the switch itself, they looked perfect to be honest. inside and out. No melting, burning marks, electric short looking type symptoms, nothing.

But when the lights did work for the 5 minutes after putting the dash together. The Main Head light switch illumination Lights were WAY dim compared to the HAZARD switch. Like it was dying lol

It was not like that before the lights went out. The illumination lighting was the same on both switches. That's why I am praying its the head light switch haha
 

Blown88GT

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Nov 13, 1999
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Palm Beach Gardens, FL
After looking at the diagram, I have to conclude that not all of the dimmer controlled lights are in the instrument cluster. There are the heater/AC controls, radio illumination relay and the ashtray. The radio illumination can be discounted if the radio is disconnected.

The user has a full short circuit when full power is applied to the lighting circuit; the dimmer serves to limit the current until the brightness is turned up all the way to maximum illumination. The short may be intermittent, and it may require the wiggle and jiggle mode of testing.
Read Post #3 again. Sounds like a skinned wire is touching the chassis. Impossible to wiggle when everything is put back together.
I just found one of these in my neighbor's electrical box; the fake electrician put 1 layer of tape over it. It literally fell off when I opened the box to expose the connections.
 
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Mrg2783

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Read Post #3 again. Sounds like a skinned wire is touching the chassis. Impossible to wiggle when everything is put back together.
I just found one of these in my neighbor's electrical box; the fake electrician put 1 layer of tape over it. It literally fell off when I opened the box to expose the connections.
I bet you're right. My gut tells me its somewhere near the fuse panel. Up in that area from maybe putting in the new speedo cable and clutch cable. But again, all of it worked after that so uhg lol.

Ill find this B yet, Thanks for the help. Ill keep you in the loop.
 

Blown88GT

Founding Member
Nov 13, 1999
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Palm Beach Gardens, FL
I just bought that short circuit tracer shown in the video above. That tool will find the short. The guy in the video sells them for $40/shipped.
I also bought the other one he was using for about $20. Found them both on eBay & on Amazon. I'll use them to find my under hood/accessory light short.

Watch the entire video.
 
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Mrg2783

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What does the current (old) switch & plug look like? You can tell by looking at it if it was overheating. The switch is not only a switch but a thermal circuit breaker.
While I'm waiting for the tester to come I decided to open her up and remove all of the items as you suggested with the multimeter attached on the 200 ohms setting and nothing gave a significant jump.... the only thing I haven't disconnected is the AC illumination. That's next.

I did unscrew the fuse panel and bend it out of the bracket , as it laid down it did raise the ohms for Split Second up to 17 from around 7. But no go when I wiggled it. Maybe from me shifting it. Who knows.

My one question, well more bouncing it off you, is the circled harness location in the attached, s208? Pretty sure it is based on the attached location index.

Which brings another question I guess, that tool needs to be directly on the wire... What's the easiest way to access that area? So I can actually open it up and get to the wires. I have not gone that deep with the interior. The upper center console section comes out as one piece I believe, no? Correct me if im wrong. Thanks.
 

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