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Headlight(s) burning/blowing out

Posted: Thu Mar 08, 2012 8:08 am
by wilfreeman
Hey guys,

Does anyone know why an 'a1 headlight might burn/blow out? At first I put an old and a new bulb in it. The old bulb, as soon as I turned the lights on, started producing a white cloud inside the bulb, then the low beam burnt out. The new one did not do this. The high beam on the old bulb worked for a total of a couple of minutes, then burnt out. I figured it was an old bulb, and was just time to burn out - since the new one was still working correctly.

I bought a set of bulbs (used) off of a member here and received them earlier this week. Upon testing them, the first one worked fine high and low beam (leads touched to the battery). The second one started clouding up immediately).

Last week, when I was troubleshooting the rear lights, I turned the lights on (it was on high beam when turned on), and the new bulb's high beam went out! Low beam is still working. Inside is not cloudy like the old bulb.

This time I thought it might be because the grill was not getting a good ground because the fenders were not on - they are on now. Then, I thought - the bulb that I touched the leads to the battery did the same thing (I know it was grounded).

Anybody had this problem? Any ideas? I can't afford to test new bulbs @ $42 + shipping each.

Image

How do you like the oil spill? That is what happens when you don't tighten the oil filter housing bolt enough. You can see the cloudy driver's side bulb.

Thanks,

Posted: Thu Mar 08, 2012 12:24 pm
by Jim
It might be that air has gotten into the bulb. The
white stuff could be tungsten oxide. How to test
this in advance is beyond me.

Jim in Darkest Arkansas

Headlight

Posted: Thu Mar 08, 2012 1:15 pm
by jeeptj1
I had the same problem and redid my grounds and it has worked fine since. Dont really remember the getting cloudy part though. John jr

Posted: Thu Mar 08, 2012 1:42 pm
by wilfreeman
Jim,
Yeah, I thought about that - old bulb and all could have a leak.

John,
What grounds did you re-do? Everything I have is fairly freshly painted - I had to scrape the fender for the horn and B.O. light (grounds) to work. I figured that since the bulbs worked to start with, the grounds at the bulb housings were ok. Maybe they're not rounded good enough? My B.O. marker lights in the grill are working - after some twisting to scratch the paint off.

What would cause the new bulb (high beam) to go out and not the low beam. Now that I think about it, I believe it's the other way around - low beam is out.

Headlight burn out

Posted: Thu Mar 08, 2012 4:36 pm
by jeeptj1
Wilfreeman, do a search on here for headlight and you will find some more info. I actually think i might have added a new small ground wire to the headlight case and the the body. I just really made sure the grounds were scraped clean. Check the search for headlight. Wes has some good stuff on his answer for me when i had trouble. Good luck. John jr

Posted: Thu Mar 08, 2012 4:56 pm
by wilfreeman
Cool - will do! I'll check it out after while. Thanks!

Posted: Thu Mar 08, 2012 7:58 pm
by BullRun
Just an idea. Could you have different voltages going different places?

One of my M38A1's has 12 and 24 voltages being used at the same time through the use of an inverter installed by a previous owner.

I found the inverter way under the dash while tracing lighting wires one day. Never knew it was there. It's odd, weird and it works very well. :D

Posted: Thu Mar 08, 2012 8:16 pm
by wilfreeman
That does sound like a good idea - might need some tunes or a phone charger, but running off one battery is a no no. But no, I've had it all the way down to the frame, and has a new (not Nos) wiring harness. More than likely, it wil be a painted ground - hopefully, that is. Thanks for the input!