Lighting problem caused by bad ground???

[67HEAVEN]

1989 Silverado. Sometimes, when I turn on my parking lights or headlights, all the factory optional gauge needles go wonky and the green signal light indicators (on the dash) light up.

Everything like signals, brake lights, 4-ways and optional factory gauges work fine unless I turn on the parking (bumper) lights or headlights.

Bad ground somewhere?

[Palf70Step]

Could be a bad connection on the headlight switch itself.

[67HEAVEN]

Originally Posted by Palf70Step

Could be a bad connection on the headlight switch itself.

Thank you, sir. It was as simple as that.

I had the entire dash apart a couple of years ago to add a power window harness. While I had everything apart back then, I thought I'd use some dielectric grease on the connections. Maybe I added too much. After cleaning off the connections at the light switch, everything was fine once again.

[Palf70Step]

Glad you got it!

[67HEAVEN]

Now that cooler weather is here, my problem has returned, along with a clue or two.

Pushing the parking light or headlight switch to on once again causes the gauges to go wonky and both green signal indictor lights in the instrument cluster to stay on solid. But, now, I also find that the wipers won't work. I didn't realize there was a relationship between the two until I drove it at dusk in the rain. The wiper problem was noticed in warmer weather, but only occasionally, and because it was daylight longer, I hadn't related it to the headlight switch issue since they weren't on.

I find that if I let everything in the cab warm up somewhat (with the heater), both problems go away.

Strange.

Any additional ideas about where to look? Thanks.

[Palf70Step]

Still could be just a bad switch. Cooler weather may mean moisture/condensation in something (least that is a problem down here in swamp land. Not sure about you guys at the north pole ).

[67HEAVEN]

Thanks, Bill.

This afternoon, I went for a spin. Temp was 2* C / 34* F. No problem was evident, and yet it was colder than the last few days.

I had assumed that the heater warming up the truck made the difference. Now, I guess that theory may be wrong.

However, you mentioned moisture/condensation. It was raining hard when the problem last exhibited itself. Today was dry. Maybe it is moisture/condensation. I'll watch it for awhile to see if that's the pattern.

Meanwhile, I'm wondering if there's a relationship between the wipers not working and the lights and gauges going wonky. They seem to go hand-in-hand.

Thanks.

[Palf70Step]

Turn signal stalk?

[TennesseeZ]

don't know if this is the case in your case, but both the headlight/park light switch and the wiper circuit board have been items I've had to replace in several of my trucks. Try this: when the wipers don't work, wiggle the plug at the wiper box underhood. Also if the headlite switch is oily/greasy it's bad. Dosen't really sound like a ground to me, but possible.

[67HEAVEN]

Originally Posted by TennesseeZ

don't know if this is the case in your case, but both the headlight/park light switch and the wiper circuit board have been items I've had to replace in several of my trucks. Try this: when the wipers don't work, wiggle the plug at the wiper box underhood. Also if the headlite switch is oily/greasy it's bad. Dosen't really sound like a ground to me, but possible.

Thank you. I'll try it and report back. It's sporadic, so it make take a few days to happen again.

[67HEAVEN]

Reporting back that the problem hasn't happened again, but the weather is very cold, not wet and humid like before.

I'll post again if I learn more.

Thanks.