help AGAIN please lol electrical this time

[silver1983gt5.0]

heres my issue when i have my ignition to run my dash lights are on none of my gauges (stock) are working and this is with the lights off. now the cool part when i turn my lights on magically the dash lights go out all except the high beam indicator wich is on on low beam off on high and my hazzard lights are on steadily not flashing and yes the hazzards are working as is the directionals and everything else. no idea where to start and it just started doing this.

 

[jrichker]

Please edit your post and use proper punctuation and capital letters.
Electrical problems are difficult enough to solve without added complications. Having to translate someone's explanation of them into an understandable format adds to the difficulty of solving the problem. It is very easy for some important detail to get lost in the translation.

 

[silver1983gt5.0]

I apologize after reading the post it was out there if you werent sure what i was thinking sorry again. double spacing may be a good idea as well so here is the problem.

My dash lights come on with key on with out the light switch on. Also the high beam

indicator and the hazzard indicator lights are on. When i turn the lights on, the dash lights

go off and my stock gauges stop working ie. oil pressure, water temp, and volts.

The high beam indicator light is always on and so is the hazzard indicator. When the

switch is not on, the exterior lights are not on either as it should be. As well as when the

switch is on all exterior lights are on. Again as it should be. All exterior lights work properly

brakes, directionals, headlights, taillights.

Also today when i was trying to figure it out, the car was running with lights on and when i

turned the car off it stayed running till i shut the lights off. Also noticed when i turn my lights

on with car not running the aftermarket tach jumps. im not sure where i should be looking for

the problem.

 

[jrichker]

Thank for your efforts. Your post is much easier to understand now.

You probably have a ground problem. It should be fairly simple to tell if the required ground is present and in good condition.

The secondary power ground is between the back of the
intake manifold and the driver's side firewall. It is often missing or
loose. It supplies ground for the alternator, A/C compressor
clutch and other electrical accessories such as the gauges.
Any car that has a 3G or high output current alternator needs
a 4 gauge ground wire running from the block to the chassis
ground where the battery pigtail ground connects.
The 3G has a 130 amp capacity, so you wire the power side
with 4 gauge wire. It stands to reason that the ground side
handles just a much current, so it needs to be 4 gauge too.

The picture shows the common ground point for the battery & extra 3G
alternator ground wire as described above in paragraph 2. A screwdriver
points to the bolt that is the common ground point.
The battery common ground is a 10 gauge pigtail with the computer ground
attached to it.

Picture courtesy timewarped1972

If that does not fix it, You get to look at the instrument cluster connectors and wiring.

 

[silver1983gt5.0]

Thank you and I will look for that ground. I did forget to write, my battery is now trunk mounted, but this problem just started maybe three days ago and the battery has been in the rear for a few months now. We did just rebuild the motor and installed it so maybe something came loose i will be looking tomorrow. Thank you for your time though.

 

[jrichker]

Rear mounted battery ground wiring. Follow this plan and you will have zero
ground problems.

One 1 gauge or 1/0 gauge wire from battery negative post to a clean shiny spot
on the chassis near the battery. Use a 5/16” bolt and bolt it down to make the
rear ground. Use a 1 gauge or 1/0 gauge wire from the rear ground bolt to a clean
shiny spot on the block.

One 4 gauge wire from the block where you connected the battery ground wire to
the chassis ground where the battery was mounted up front. Use a 5/16” bolt
and bolt down the 4 gauge engine to chassis ground, make sure that it the metal
around the bolt is clean & shiny. This is the alternator power ground.

The computer has a dedicated power ground wire with a cylindrical quick connect
(about 2 ½”long by 1” diameter. It comes out of the wiring harness near the
ignition coil & starter solenoid (or relay). Be sure to bolt it to the chassis ground
in the same place as you bolted the alternator power ground. This is an
absolute don’t overlook it item for EFI cars
Note: The quick disconnect may have fallen victim to damage or removal by
a previous owner. However, it is still of utmost importance that the black/green
wires have a high quality ground..

The screwdriver points to the common body ground for the alternator, battery and computer.

Picture courtesy timewarped1972

Crimp or even better, solder the lugs on the all the wire. The local auto stereo
shop will have them if the auto parts store doesn't. Use some heat shrink tubing
to cover the lugs and make things look nice.


For a battery cut off switch, see Moroso : Category Display
is the switch http://www.moroso.com/catalog/images/74102_inst.pdf is the installation instructions.
Use the super duty switch and the following tech note to wire it and you will
be good to go.

Use the Moroso plan for the alternator wiring and you risk a fire. The 10
gauge wire they recommend is even less adequate that the stock Mustang
wiring.

There is a solution, but it will require about 40' of 18 gauge green wire.

Wire the battery to the two 1/2" posts as shown in the diagram.

The alternator requires a different approach. On the small alternator plug
there is a green wire. It is the sense lead that turns the regulator on when
the ignition switch is in the run position. Cut the green wire and solder the
40' of green wire between the two pieces. Use some heat shrink to cover the
splices. See Ford Fuel Injection How To Solder Like a Pro for some excellent
help on soldering & using heat shrink tubing.

Run the green wire back to the Moroso switch and cut off the excess wire.
Try to run the green wire inside the car and protect it from getting cut or
chaffed. Crimp a 18 gauge ring terminal (red is 18 gauge color code for the crimp
on terminals) on each wire. Bolt one ring terminal to each of the 3/16" studs.
Do not add the jumper between the 1/2" stud and the 3/16" stud as shown it the
Moroso diagram.

How it works:
The green wire is the ignition on sense feed to the regulator. It supplies a turn
on signal to the regulator when the ignition switch is in the Run position. Turn the
Moroso switch to off, and the sense voltage goes away, the voltage
regulator shuts off and the alternator quits making power.

The fuse & wiring in the following diagram are for a 3G alternator. The stock alternator uses a dark green fuse link wire that connects to 2 black/orange wires. Always leave them connected to the starter solenoid even if you have a 3G alternator.

See the following website for some help from Tmoss (diagram designer)
& Stang&2Birds (website host) for help on 88-95 wiring
Mustang FAQ - Engine Information Everyone should bookmark this site.

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

 

[silver1983gt5.0]

Would a bad headlight switch cause these problems? Just curious, i do have to run a cable from my battery to motor other than that the wiring is like the picture and write up

 

[jrichker]

Like it says "Follow this plan and you will have zero ground problems"...