Could LED sealed beam melt a headlight plug? (fixed!)

Ava92
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Location: BC, Canada

Could LED sealed beam melt a headlight plug? (fixed!)

Postby Ava92 » Sun Jul 07, 2019 6:07 pm

Driver's headlight won't work on low. On high, both sections work.
Swapped the driver and pass'r lights, problem persists, so it's not the bulbs.
Put a brand-new switch, but that wasn't it (whoops)

Looked at the plug (brown one that the sealed beam plugs into), and the brown plastic is a bit melted.
Hit it with multimeter, and with low-beam on, looking at the plug head-on like this:
| _ |
The middle and right parts both read ~6.5V. it was alternating also, would go near-0 then come back to 6.5 every 1 second or so
Left part read 0
The melting was near the middle part


Passenger reads
| _ |
Left: 12.5V constant
Middle: nothing
Right: jumps to like 0.8 then sits back at 0, every time I check it


Passenger plug is ok and no melting

Plug being hot means it is encountering resistance, right? Could it be from the LEDs? Had halogens for years previously without issue
Had these LEDs in for a couple years or so
This problem appeared then went away about 6 months ago. Thought it was some shabby wiring which I replaced

Also: the driver's retract relay (right in front of battery) was collecting rainwater down in its wire loom. I dried it out and re-sealed it up. However, the up/down function has always worked fine. Not sure if that has anything to do with the light issue

They are Trucklite 27450C

Sure want to keep them if possible, super dark around here with a lot of deer

Thanks for readin my post
Last edited by Ava92 on Wed Aug 21, 2019 11:08 am, edited 3 times in total.

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jondee86
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Location: Wellington, New Zealand

Re: Could LED sealed beam melt a headlight plug?

Postby jondee86 » Tue Jul 09, 2019 4:26 am

LED lamps should not draw any more current than the OEM incandescent lamps
so if the plug melted it is likely there was some kind of short or arcing from a bad
connection. You need to replace the damaged plug... maybe you can find one from
an 80's Toyota at the junkyard. Take the plug complete with a few inches of wire
and use it to replace the damaged one. Be careful to match the same wires to the
same pins.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

Ava92
Club4AG Enthusiast
Posts: 84
Joined: Tue Feb 19, 2013 7:06 am
Location: BC, Canada

Re: Could LED sealed beam melt a headlight plug?

Postby Ava92 » Thu Jul 11, 2019 9:23 pm

appreciate it jondee, you've helped me a lot over the years (mostly from lurkin)

Will report back

Ava92
Club4AG Enthusiast
Posts: 84
Joined: Tue Feb 19, 2013 7:06 am
Location: BC, Canada

Re: Could LED sealed beam melt a headlight plug?

Postby Ava92 » Mon Jul 22, 2019 11:09 pm

Thanks jondee!
used one off a jeep YJ and sealed it with waterproof marine shrinkwrap

Thought it was a symptom of a larger problem. Glad it was such a simple fix