One headlamp works on Chevy truck

I've got a 2002 K3500 and have had lots of problems with my headlamps. it all started about 2 years ago, when I realized that my fog lamps didn't work anymore. I didn't think it was a big deal, because they weren't much use anyways. Then about 1 year ago, my left side daytime headlamp stopped working. Somewhere around this time, one of the leftside clearance lights on my fender (dually) gave up the ghost too. I can't help but notice that there are many Chev/GMC tucks running around with only one headlamp working during the daytime, so I'm wondering if this is a natural occurrence, and wonder if anyone has come across the problem and found the cure. Now just last week, the left side headlamp (low beam only)quit. The high beam still works, but people are flashing me when I put them on. I checked the fuses, everything is OK. I haven't checked the bulb since the night time headlamp stopped working, but when it was just the daytime lamp, the bulb was found to be OK. Anyone come across this issue, and do you know what the fix is? I have also moved around the relays in the fuse box, same results, so I don't think that the relay is the cause.

Any suggestions?

Reply to
rdj
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First, check the bulb(s) in question. Never assume that other vehicles with a bulb out are related to your problem. Second, check for power to the bulb. Third, check the ground.

Process of elimination....

Reply to
Raymond J. Henry

A three-year-old truck...my bet is that the bulbs are starting to burn out. His observation about "one-eyed" GM trucks seems consistent with my observation though. I also see quite a few relatively new GM vehicles (primarily) with brake lights out too...often more than one out on the same car. I wonder who supplies GM the bulbs they use?

Reply to
James C. Reeves

It's not the bulbs, they get those from the same major makers who supply all the rest of the world's carmakers. It's GM's persistent insistence on excessively-high voltage regulator setpoints (edging up towards 15.5v!). Bulb life is affected as the *THIRTEENTH* power of voltage change, which is why high-voltage GM vehicles eat bulbs like popcorn. In typical fashion, rather than correct the problem and set their voltage regulators to 13.8 to 14.2, GM commissioned a couple of new bulb types rated at 14v rather than 12.8. *eyeroll*

DS

Reply to
Daniel J. Stern

How long has this been going on, Daniel?

Reply to
<HLS

Somewhat off-topic, but recently our warranty clerk was asking around for a mechanic to "burn up" an 1157 bulb because someone forgot to tag a bad bulb during warranty replacement. I was in a hurry, so I series wired a 9.6 volt battery pack along with the battery in the car I was working on to a spare bulb socket. After about 10 - 15 minutes at ~23 volts and some intense glowing I decided to tap on the bulb, which finally did the trick of causing it to fail. Anyhoo, I was surprised at how long it held up. BTW, only the bright filament was powered.

Toyota MDT in MO

Reply to
Comboverfish

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