1990 spirit problem

[71 demon child]

My buddy has a 1990 spirit or maybe it's an acclaim,(3.0 liter)but anyhow he says that once in a while when he is driving the dash lights go out and all the gauges "peg out" except the alternator gauge it falls back to nothing.Oh, and both the turn signals stay fully illuminated(but are still operational when using them). This does not cause any performance problem.He says if he hits a big bump it will go back to normal.I haven't got the car to do it yet.But i am leaning toward a ground problem.I checked the grnd. from batt. to block and the grnd. from block to firewall,all ok.It sounds like it's a very isolated problem disturbing only the dash.He hasn't noticed wether it has done it during the day because the lights are not on and it doesen't catch his attention.I figured maybe the headlights might be contributing to the problem but no evidence so far to prove that.I haven't got up into the dash yet to do a wiggle test(figured it might be in the dash).But before i go tearing into it and making more work i figured i would see what you guys think.I definitely would think something is loose given the bump scenario . Thanks!

carl

[DartKnight]

Sounds like loose connections/wiring to me, also. Fox-body Mustangs and various other Fords were notorious for it; my brother had two early 90's Mustangs, and sometimes the gauges would go dead at random in both cars. One hard donkey-punch to the dash and everything would go back to normal. 

[71 demon child]

Tried the donkey punch.To no avail.Anybody else

[blown71duster]

Carl, I know you can also get some strange problems when there is a short from ground to a power, The power backfeeds into circuits and causes similar problems like you have , but when the circuit feeds lights like your turn indicators it doesn't pull enough amps to blow fuses. I just had a ford exployer in the shop, he thought he would wire up his own radio, $17 dollar radio. and he cut wires and shorted them. Then he got the idea of tin foil under the fuse. The radio power and ground melted together under the dash and it lit turn signals solid volt gauge would bury toward 0 volts and some dash lights illuminated. These things shared same ground. End up costin him $60 to fix his mess. You might try unplugging things when problem exists possible short to power in light switch. I had power on known ground circuits when I tested with test light. Those intermittent problems are the worst, hope this helps..... My favorite was a 89 mustang with no dash lights and the owner duct taped a mini flashlight to the column, I got a kick out of that!

[71 demon child]

Hey thanks,Yeah i've hd some pretty wierd ones.I had a Freightliner that one of the rookies forgot to put the ground strap on the bolt that goes to the starter.It caused the whole truck to be energized 12v .Floors and everything.Well guess i'll give it a try.

carl

[NitroFixx]

Check the screw on the 50 way bulkhead connector and make sure its tight

[71 demon child]

As soon as i get my buddy back over here.That oughtta be a chore . thanks

carl