My 96 gt has the tendency of giving me a very weird electrical problem. When I turn the headlights on, the radio cuts out, and so does the door chime, power windows, locks, spedometer, internal lights and outer lights. I also get the airbags off beep from below the steering column. The RPM gauge IS functional though. Here's the weird part: If I wait a while, and then put the headlight switch to on, and SMACK the top of the instrument cluster, EVERYTHING will turn itself back on again! Radio, power locks, etc. Never does the car itself not run or any other mechanical problems. I have tried tracing the wires to find a bad ground, but can find nothing! Any ideas?

Is there an electrical node or bundle of shared wires (or grounds) in common between the dash, headlights, power locks, windows, stereo, little digital clock, and airbags?

I need help! Thanks!

 

They don't share a common ground but the guage cluster and the airbag warning all share a common power source wire.It's supposed to be red/yellow.Hope this helps narrow your search.

 

My Haynes manual says the same thing, but this wire doesn't have anything to do with the power locks, windows and headlights...Thanks for the input though!

I'm inclined to think ground wire because everything shuts off (usually) when I pull the headlight switch....

 

Hve you check the wiring harnesses were they come threw the firewall and to the computer to make sure there all plugged tight??I bet its a simple loose plug

 

I have checked both harnesses that lead from the driver's side through the firewall to the computer. All's well there. But even if that were the problem, would it account for it fixing itself when I WHACK the dash?

 

Oh ok .My superduty did that and the plug was falling out of the back of the cluster try taking out the cluster and checking that plug

 

You know, I ALSO thought it was the damn instrument cluster (because of the banging, etc.)--so I used it as an excuse to put a whiteface indiglow face gages--took the whole thing apart, and everything was plugged right.

You know, come to think of it, the problem has occurred MORE OFTEN after I installed the aftermarket white face gages--I had to attach them to the lead 12v cable....I imagine that is DRAINING a little more power from the dash lights, increasing the overall drain--This only reinforces the bad grounding theory--Goddamn it!!! Where could it be!!