1990 Suburban Headlight Problem

[b79holmes]

We replaced the headlight switch which worked fine for a time.

A few weeks later the headlights after being on for a few minutes then randomly go off and on but the parking and tail lights remain on.

Is this a ground problem? Where is the ground wire & connections?

Could it be something else?

Thanks,
Bill

[tobiahr]

there should be a headlight relay for that model. that may be going bad and would have the same symptoms

correction....there may be a headlight relay

[tobiahr]

looking at the wiring diagram it could also be the high/low beam selector as the parking lights are on a branch circuit that does not go through the selector.

[tobiahr]

diagram

[Ski-me]

That looks like the newer body style 88+ trucks.

You need the R/V wiring diagram for the 1990 or 1991. (1989 does not have rear abs brakes but that doesn't really matter too much here).

I replaced my Hi/Low switch that is mounted on the steering column, down by the brake pedal. Connected with a metal rod. Good as new now. Might also check the connections at the headlamp assembly. Seen those get loose and go bad.

Part on Amazon:
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

[b79holmes]

Problem solved.

After doing a little research, I found a couple of other people who had similar headlight blinking issues on their trucks, and each time it was the headlight switch itself.

I finally got around to ordering another one and I just installed it today, which has solved the issue.

The faulty switch was a cheaper reproduction, so this time I got a real Delco NOS part to replace it with. And yes, the tuck is a V1500 Suburban.

Thanks for the help