Electrical Problems

[Dan H]

I need some help with some electrical problems on the 92;

Intermittently (60% of the time) while running or key-on, the Stereo and Climate Control will loose power, and usually the air bag warning light not functioning beep will sound (incessantly) . I have removed the stereo and pulled apart the dash and visually inspected all the wiring I can without finding any unintentional grounds or shorts.

Any ideas / help would be appreciated.

 

[pjtoledo]

Try looking for a faulty ground. Thats an open circuit. An accessory needs two things to work, power getting to it, then that "used power" going back to ground. Loose either one and nothing works.
Have a couple of elec meters hanging around? Pick an accessory, attach a meter to its power lead and go for a ride. When the accessory stops working look at the meter, power, yes or no. If no power trace from that point back to power. If yes, then hook the meter up to the ground at the accessory and repeat the driving/failure test. While monitoring the ground, when it fails, if there is power at the ground pin of the accessory then there is an open/break in the circuit going from the accessory back to ground.
The wiring in these cars is starting to show its age. Look for bad splices, loose terminals at the grounds, corrosion in/around the ground screws in the cars body. And of course, rust where two pieces of steel should be conducting a ground circuit.
You can also add a ground wire from the accessory back to ground, I strongly suggest having a fuse in any extra wires you throw in there.
Intermittant electrical problems aren't much fun. Good luck.


Perry

 

[Dan H]

I have visually checked all the wiring, splices, & grounds that I can under the dash. I have not pulled out a multimeter yet.

I was hoping to find a lead or ground that was common between all 3 systems (EATC, Stereo, AB warning light) but the wiring diagrams in my manual are practically worthless. I was also hoping there might be someone who experienced the same or similar problem that might be able to narrow it down.

 

[Dan H]

Does anyone have decent wiring diagrams for the Gen2 SHO?

Does anyone know of any leads or grounds shared between those components?

Has anyone experienced the same problem?

 

[etc1006]

You can download the wiring diagrams right to your computer right off here. There is a sticky for it, I cna't remember which section. Just pick your year and go. It'll take a little while as its several files.

 

[Dan H]

Update:

New symptoms; EATC power cycles with blinker, Tach doesn't work below 1500 rpm, Batt Light, IRCM went bad - radiator fan won't shut off. Allo of this is intermittent of course.

Can't find any bad grounds, added an extra ground from the block to the chassis. Removed the stereo. Replaced EATC with known good one. Replaced the IRCM with known good one from my brothers car. Noticed Battery going dead, charged it & checked it - good. Drove to autozone, Alternator checks bad, 12.2 volts 0.3 amps. Ordered a new one.

The question is, could all this be caused by a bad alt? The car had none of the symptoms on the full batt charge drive to autozone.

Any help appreciated.

 

[FRDSHOGRL93X3]

Have you tried replacing your battery cables? I had similiar symptoms and that was the cause.

 

[Dan H]

Negative Batt Cable is new.

Positive one appears to be good.

Can bad cables cause a bad test on the alt?

 

[FRDSHOGRL93X3]

They appear good, cut back the insulation and see if its green.