electric fan swap is upsetting my LC1 wideband please help

hey everybody, I just swapped an electric fan setup into my 89 mustang. Im using an sn95 fan from a 94 car. i did go the cheaper route with a fan controller from autozone. I did the 3g alternator swap from a 94 car as well.

I'm having an issue since the swap. My innovate LC1 wideband has been shutting off while im driving. It stays on for maybe about 10 min or so, and seems when the fan kicks on the wideband gauge shuts off. Also the fan decides not to work all the time. Im thinking when the fan pops on maybe theres some kind of voltage spike? that caused the wideband to shut off, and also shushuts the fan off also after it kicks on. it seems like the fan doesnt pop on because the car will start to overheat, and when i pull over and shut the car off and then switch the car "on" the fan turns on, but then when u start her up, the fan it doesnt run. im not really sure whats going on. im thinking about maybe upgrading the relay and wiring in a diode like the guy did in the link i provided below. if anyone has any advice please help im stumped.


http://www.fordmuscle.com/archives/2...cfan/index.php
 
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Your link does not work. Anytime you paste a link in a post and it already has the 3 dots, it won't work. The 3 dots shorten the link and indicate that something was left out to save space. Go back and copy and paste the whole link from your browser into your post.


Did you add a 4 gauge ground wire to match the 4 gauge power feed when you did the 3G upgrade?
 
You might want to use different wiring sources for you WB.

Post up exactly what you did with the fan wiring, as something isn't functioning correctly. A flyback diode (or lack thereof) should not be causing the issue.
 
sorry about the link this should work better...

Junkyard Electric Fan - FordMuscle

As for upgrading the wires for the alternator swap, I upgraded to the stock size for a 94 mustang. thats what i took the fan out of. the gauge was 8 gauge. it was alittle bigger than what was in the fox so i upgraded the power wire to 8g. i didnt touch the ground. i could have swore i read somewhere online that u just have to upgrade power and not ground. but iv been wrong before. think i should upgrade both power and ground to the 4g? 4g did look huge to me thats y i went with what was on the stock harness fore the 94 stang. and if i should upgrade to 4g wires, would it be bad to go alittle bigger to say 3g? i ask this because i hae some 3g wire laying around in the garage.
 
You need to use 4 gauge power wire to carry the current that a 3G alterntor is capable of generating. You also need a 4 gauge ground to go with that 4 gauge power wire.

Wire size current table:
53745d1205096904-how-determine-proper-fuse-wire-size-wire-gauge-current-capacity-lenght-chart.gif


Get your power and ground wiring problems corrected before doing anything else. This will save you time and money.


Grounds
Grounds are important to any electrical system, and especially to computer controlled engines. In an automobile, the ground is the return path for power to get back to the alternator and battery.

1.) The main power ground is from engine block to battery: it is the power ground for the starter & alternator.


2.) 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 as much current, so it needs to be 4 gauge too.

The picture shows the common ground point for the battery , computer, & 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
ground.jpg


Correct negative battery ground cable.
56567d1230679358-positive-negative-battery-cable-questions-86-93-mustang-oem-style-ground-cable.gif


3.) The computer has its own dedicated power ground that comes off the ground pigtail on the battery ground wire. Due to its proximity to the battery, it may become corroded by acid fumes from the battery.
In 86-90 model cars, it is a black cylinder about 2 1/2" long by 1" diameter with a black/lt green wire.
In 91-95 model cars it is a black cylinder about 2 1/2" long by 1" diameter with a black/white wire.
You'll find it up next to the starter solenoid where the wire goes into the wiring harness.


4.) All the sensors have a common separate ground. This includes the TPS, ACT, EGE, BAP, & VSS sensors.

5.) The O2 sensor heaters have their own ground (HEGO ground) coming from the computer. This is different and separate from the O2 sensor ground. It is an orange wire with a ring terminal on it. It is located in the fuel injector wiring harness and comes out under the throttle body. It gets connected to a manifold or bolt on back of the cylinder head.

6.) The TFI module has 2 grounds: one for the foil shield around the wires and another for the module itself. The TFI module ground terminates inside the computer.

7.) The computer takes the shield ground for the TFI module and runs it from pin 20 to the chassis near the computer.

8.) The computer's main power ground (the one that comes from the battery ground wire) uses pins 40 & 60 for all the things it controls internally.


See http://assets.fluke.com/appnotes/automotive/beatbook.pdf for help for help troubleshooting voltage drops across connections and components. .

attachment.php


Extra grounds are like the reserve parachute for a sky diver. If the main one fails, there is always your reserve.

The best plan is to have all the grounds meet at one central spot and connect together there. That eliminates any voltage drops from grounds connected at different places. A voltage drop between the computer ground and the alternator power ground will effectively reduce the voltage available to the computer by the amount of the drop.
 

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thannks for all the info man. much appreciated. i went and got a bunch of 4g wire yesterday. hopefully if it doesnt rain today i can get that part out of the way. now the factory wire uses a fusible link on the power wire. are u supposed to run a fusible link when u do the rewiring or can u just use a big enough fuze, if so what size fuze would be reccomended?
 
You can do either, though most folks use a fuse.

A 125 Amp fuse is commonly used, though the cable size and alternator output rating factor into the decision.
 
Oversizing the fuse does absolutely nothing good for your car. By oversizing the fuse, you virtually guarantee that short circuit will burn up the wire and possibly the rest of your car.


For a 135 amp circuit breaker, see Error 404 price is $34.05

For a 120 amp circuit breaker see Del City - Wiring Products and Professional Electrical Supplies price is $29.45

High current Fuse holder from local NAPA dealer - Item#: BK 7821143 Price: $10.49
Product Features: Thermal Plastic Holder For AMG Type Fuse Rated From 100 To 300 amp

CatalogItemDetail.aspx


NAPA or one of the local auto parts stores may also have the fuse you want.
 
I found the problem! I noticed the wideband an fan wouldn't work when I would start the car up but if I turned the key slightly more everything would work fine. So I bought a new ignition switch. When removing the old one it fell apart when removing the wire. So that was the problem. No issues since I swapped the switch. I also upgradedto the 4g wire like you guys mentioned just to have the alternator done right.