The car is an '89 Iroc Z, TPI 305, 5 speed with 203,000 miles. As I was leaving work today, I turned on the headlights with the engine running, and the gas gage, voltmeter, temperature gage and tachometer all went to zero. Also, the high beam indicator lit up and the high beams weren't on. When I turned the high beams on, the high beam indicator went off. Also, both turn signal indicators stayed on constantly. The lights outside functioned normally and the white lights that backlight the gages worked normally. So I started home without the lights and got as far as I could until it became too dark and I had to turn the lights on. When I turned the lights on this time, everything worked normally. When I got home, I played around, turning and jiggling the headlight switch, and everything still functioned normally. Any ideas on what's going on here? All advice is appreciated.

 

Was it wet out? or did you go through any large puddles prior to shutting your car off? I had a minor problem that was caused by some water getting in between a few contact points. Has it done it again yet? Can you reproduce any events that happen the same day and try to make the problem return?

 

It was not wet out that day or the previous days before, and I did not go through any puddles. Actually it was cold (25º F) and dry out. I tried it out several times after I got home last night and everything was still normal. I drove the car to work today (22 miles) with the lights on and everything was still normal.

 

I'd look for a loose or dirty ground wire. I've seen the backhoes I work on do crazy things when a ground is loose. They'll be working fine then all of a sudden they won't start, or the gauges light up when you step on the brake pedal.

 

yea, no kidding. that's what it turned out to be for my 91 with the fuel pump cycling on everytime i hit ANY lights, other than blinkers... strange thing about that was that it was the grounded wires behind the driver side head were paired up wrong... strangest thing i ever saw.

KAM

 

This sounds exactly like a problem I had a few years back. Intermittently, either the headlights or the right turn signal would cause dash wackiness...gauges pegging, high beam indicator staying on, etc.

Root cause was the gauge cluster's flexible circuit sheet having a broken conductor. If you remove the gauge cluster, it's a plastic/Mylar sheet with flat copper conductor overlay. The light bulbs actually seat on it and help hold it in place against the white plastic gauge cluster housing.

I was able to fix mine w/ a soldering iron and a rear window defogger repair kit, 3 years and still going. If I had it to do over again, I'd hit the junkyard and find a replacement tho...major PITA fixing that thing the way I did it.