92 B2200 Headlight keeps going out

I had one of my headlights (low beam) burn out on the passenger side. So i replaced both with brand new sylvanias and the passenger side is out again not even a week later. Could it be fuse?

Edit: Both high beams work

It could be any number of things. What I would start by doing is make sure I have voltage going to the headlight at the plug. Get a test light and check it at the plug. If no voltage at the plug then you need to follow the wire back to where it looses voltage. You need to check if you have a ground at the plug too, but if the high beams work then you probably have a good ground. The plug might be corroded at the headlight, and when you plugged in the new light it made contact for a short period of time, and then lost contact again. And also check that the headlight is still good, swap the lights from side to side. It's all trouble shooting at this point. Good luck, Dean

Thanks for the speedy reply, I'll try everything and let you know what happens

I have had an alternator cause voltage spikes that would blow headlights also. Terribly frustrating and gets expensive quickly.

I had the same thing happen with my plate lights, replaced them both and one went out very shortly after. Could that be caused by the alternator?

I had a voltage regular go out once on my old Toyota truck, high voltage. I could see the dash lights get real bright and then burn out; in fact all my lights burned out except the headlights and turn signals/flashers. So I made it home using headlights and flashers on. I presume that flasher bulbs did not burn out from excess voltage because they got a chance to cool, but headlights did not burn out, might be a designed-in safety thing.

So I think you'd notice if there were voltage increases enough to burn out a bulb's filament. The thing to do is check for voltage at the headlight connection itself; there's one terminal for low beam positive voltage, one terminal for high beam positive voltage, and a ground (so you'll need to switch lever to check both positive circuits).

Also, once unplugged, the ohms resistance for each filament in the bulb can be measured with the multimeter to see if both filaments are really burned out.

That bulb that burned out is covered by warranty - return it. I had one new Sylvania lose a filament a few years ago after a few months, returned it for another.

But the key is to test the circuit and the bulb filaments. And same for license plate lights, tail lights, etc. An inexpensive digital multimeter is " "must". These are under $20 at many palces, and sometimes free with coupon at Harbor Freight.

Cusser sent you a message

As an update, I got around to getting my hands on a multimeter and the headlight that went out has 11.73 volts going to it while the other headlight that works is getting 12.06 volts. I have yet to measure the voltage with the motor running.

More stuff thats happened: Wipers stopped working, Probably something to do with the wiper motor.
The headlights low beam filament is broken, I checked the resistances on the highbeams and they are still intact

Get it replaced, warranty 1 year. I did that a few years ago. Yes, was pi$$ed because I had to pull off most of the grille, again.

Did you check the battery voltage? From what you posted it seems that you have a battery that is weak, and if that is the case, the alternator will overcharge in an attempt to compensate for the low battery voltage. That could be causing voltage spiking. A good battery when flat should show 12.06 volts.