Drivers side head light burn out.

1959 - 1978, M151, M151A1, M151A2, Technical questions and discussions, regarding anything related to the M151.
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Gunbunny198
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Drivers side head light burn out.

Post by Gunbunny198 » Thu May 20, 2021 4:41 pm

So I know this is common on new military vehicles as well but what causes it. Lost drivers side headlight this morning. New one installed this afternoon and then same one burnt out again. Any ideas on where to start?


Rickf
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Re: Drivers side head light burn out.

Post by Rickf » Thu May 20, 2021 5:38 pm

Are you using old stock or new replacement lights? The new replacement lights have a lifespan measured in minutes. Seems like nobody can make anything in 24 volt electrical anymore.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Gunbunny198
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Re: Drivers side head light burn out.

Post by Gunbunny198 » Thu May 20, 2021 5:45 pm

Wagner old stock I believe. It was originally a GE old stock. I just find it odd it's almost always the drivers side. Source for NOS?

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W. Winget
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Re: Drivers side head light burn out.

Post by W. Winget » Thu May 20, 2021 6:16 pm

Went through three take outs on one restoration once, I find that applying some voltage like 12V to a 24V old bulb for a short bit helps to burn off any residual corrosion that may have occurred while it sat around.
The front grill shakes a whole lot, so if the filament is questionable at all it's like using a drop light with standard bulb, just can't take the vibration. :idea: Try turning the lights on after installing them without the engine running for a minute perhaps to see if it stabilizes the filament better.

Short of switching to LED clusters, little you can do about it. Perhaps Star Electric has a better recommendation if he even sells them.
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Rickf
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Re: Drivers side head light burn out.

Post by Rickf » Fri May 21, 2021 6:27 am

Also check to be sure the ground wire is good on the fender. intermittent ground could be shocking the bulb. I put LED's in mine, I prefer safety over originality. I can now actually see the road at night!
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

markrdje
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Re: Drivers side head light burn out.

Post by markrdje » Fri May 21, 2021 7:21 am

My dim headlight always burns out, so since most of my driving is in town, I figure to adjust headlight to aim down more so it doesn't shine in the eyes of on coming drivers.
change user name to mark

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Kurt Lesser
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Re: Drivers side head light burn out.

Post by Kurt Lesser » Fri Jun 04, 2021 2:00 pm

Rick called it here people, poor grounding shocks the filament and will cause premature failures. Check to make sure the #91 wire connections are clean and tight on the lamp and the fender.
Last edited by Kurt Lesser on Sat Jun 05, 2021 11:29 am, edited 1 time in total.
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Re: Drivers side head light burn out.

Post by Fil Bonica » Sat Jun 05, 2021 8:57 am

Been using LEDs for years.
Dont do that much nite time driving but when I do they are great!
Rick, do you remember when I first got them and questioned that they may have been blinding?

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Rickf
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Re: Drivers side head light burn out.

Post by Rickf » Sat Jun 05, 2021 5:14 pm

I do remember, I have asked several people about mine when I am in Virginia driving at night and no complaints at all. I set them initially with a pro headlight aimer, I actually raised them up a bit since the cut off line is so sharp they still do not bother oncoming drivers and offer amazing vision for my old eyes.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Gunbunny198
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Re: Drivers side head light burn out.

Post by Gunbunny198 » Sat Jun 19, 2021 11:20 am

Hi all,
Thanks for the replies. I've been away doing army training so haven't had much time. Two quick questions if I may.

Whats a good sorce for LED?

Also any chance the alt is pushing too much power to the bulb being on the same side? The gauge is in the green so I wasn't considering that at first.

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Re: Drivers side head light burn out.

Post by Rickf » Sat Jun 19, 2021 1:25 pm

My LEDS are the same ones they used on the Hummers way back when the first started using them. Came with the buckets and everything. And the voltage coming from the alternator will be the same for everything, it goes to the main harness at the starter switch before being sent out to the rest of the system. Loose grounds, Loose mounting hardware for the bulb. Those are the main things I can think of that would cause your problem. Have you checked the voltage with a voltmeter at the batteries with it running? Do not depend on the gauge for an exact reading.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone


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