'99 Tahoe Headlight problem

[palallin]

Hody, folks. It's been a while since I've been here; work has kept me from having fun with my trucks

About 6 months ago, however, my soon-to-be-driving-on-his-own some broke the knob off the headlight switch on the Tahoe. I bought the replacement and installed it (a commendably easy job).

About two months ago, the driver's side low beam bulb went out, and I replaced it (not quite so easy a job)

About ONE month ago, I was driving home at the end of a 2 hour drive when the headlights blinked off. NO OTHER LIGHTS FAILED; even the marker lights stayed on. After approximately a minute, the lights came back on of their own accord. Since then, this has happened on about a dozen ocassions, but now it happens after only abut 15 minutes of driving. It will then recur about 5 minutes later.

Needless to say, this is not a safe condition, but it's getting harder to NOT drive in the dark as the year wanes.

I have checked the fuse/breaker panels, and there is no breaker int he circuit I can find unless it's in the switch assembly itself, which I suspect is the case. I can hear the trip as a breaker goes in the dash, but I cannot get me head next to the switch while driving I also hear a fainter click when the lights come back on.

Has anyone encountered this before? It did nto happen right after I changed thw switch, but it's hard to suspect the bulb when it took so long for the problem to show up after I changed it. And I don't understand how that could be it, anyway.

IS there a breaker in the switch, or is there one in the dash somewhere? I cannot find my manual when I need it!

Any thoughts/ideas/experience appreciated!

[1badgmc]

Unfortunately, your main issue is beyond me. I've never had any experience with that one. But, you said it was "not quite so easy a job" to replace a headlight bulb, so I'm guessing you were trying to get to it from the backside of the radiator support? If so, here's a little tip that makes the job super easy

[palallin]

That IS helpful; thanks!

[palallin]

Well, it happened again tonight.

Anybody have even a guess?

[Cape Codder]

I never had it happen with a GM truck but it was very common on Fords. I maintained a fleet of wreckers and we ended up putting all the running lights on a relay on the Ford trucks and solved the problem. Is the new headlight switch a GM part or aftermarket? I would change the switch as it is a cheap easy job. I can't imagine a working bulb would cause the problem.

[palallin]

Well, based on my conjectures and Cape Codder's, I went ahead and dropped the $57 for the light switch and changed it yesterday morning. A 35 minute trip to town without the headlights going out instilled bravery into my heart, so we took the Tahoe to my Mother-in-Law's yesterday, requiring a two-hour trip home in the dark. The lights stayed on!

Three loud Huzzahs!

Apparently, the switch was the problem. After another trip or two, just to be sure, I'm going to dissect the bad switch to see what makes it tick. I will report back with what I find inside. Maybe someone else will be able to use the info.

[1badgmc]

Sweet. Good to hear it seems to be fixed and wasn't something more serious than a simple switch swap.

[rickpilgrim]

Had the almost the same problem with my 98 k2500, bought as parts truck, no switch so installed irish store cheap headlight switch all good for 6 months and then intermittent low beams, bad switch. Repeat after another 5 months. Bought OEM switch from dealer 2 yrs plus ago no problems so far. No more bargain store bargin store parts as important as this for me ever again