Burnt Headlight switch
Thread Starter
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Tuned
Joined: Jul 2010
Posts: 344
Likes: 8
From: Kennedy, NY 14747
Burnt Headlight switch
Good morning all,
This is my 97 OBS PSD.
I was having a problem with my headlights not working at times.
I picked up another pull switch from the boneyard. When I pulled my old switch I found the plastic connector on the harness and the old switch itself were burned some. The wire itself (black w/red tracer, hot all times)
Was ok, not brittle at all. I was able to file down the connector where it burnt and bubbled a little. The new switch is fine and all is working now.
Is there a history of these switches burning up? The truck has stock lights, no additions. Looking for clues as to why this happened.
Thanks,
Joe
This is my 97 OBS PSD.
I was having a problem with my headlights not working at times.
I picked up another pull switch from the boneyard. When I pulled my old switch I found the plastic connector on the harness and the old switch itself were burned some. The wire itself (black w/red tracer, hot all times)
Was ok, not brittle at all. I was able to file down the connector where it burnt and bubbled a little. The new switch is fine and all is working now.
Is there a history of these switches burning up? The truck has stock lights, no additions. Looking for clues as to why this happened.
Thanks,
Joe
Postmaster
Joined: Sep 2007
Posts: 4,195
Likes: 6
From: Medford Oregon
Joe, probably just a bad connection where it plugs into the switch. Headlights draw a lot of current and a poor connection anywhere generates heat. Replacing the switch and cleaning up the harness, like you did, should solve the issue. I don't think it's a real common problem but not unheard of.
Thread Starter
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Tuned
Joined: Jul 2010
Posts: 344
Likes: 8
From: Kennedy, NY 14747
Joe, probably just a bad connection where it plugs into the switch. Headlights draw a lot of current and a poor connection anywhere generates heat. Replacing the switch and cleaning up the harness, like you did, should solve the issue. I don't think it's a real common problem but not unheard of.
thanks Jim,
Ya, I cleaned it all up good and put some dielectric grease on the terminals. I didn't see anything else I could do.
I just don't like fires under my dash. I do remember a recall some years ago on headlight switches causing fires. But I don't remember what make or models it applied to. I know you guys would know if it was our trucks.
Thanks again,
Joe
Fleet Mechanic
Joined: Aug 2007
Posts: 1,508
Likes: 2
From: The boonies by Dallas OR
I went through 3 switches in a row when the original one failed. When the factory switch went out it took out the plug so I had to replace both. The replacements only lasted about a month and then I'd start having the lights blink again.
I put in relays in front of the left battery and now the headlight current doesn't go through the switch. That was 3 years ago and I haven't had a problem since. Plus the lights are noticeably brighter.
I put in relays in front of the left battery and now the headlight current doesn't go through the switch. That was 3 years ago and I haven't had a problem since. Plus the lights are noticeably brighter.
Logistics Pro
Joined: Jun 2009
Posts: 4,116
Likes: 6
From: metairie, LA
i just recently had a burnt headlight switch. there are alot of amps running through it. there is a kit made or DIY instructions around here somewhere to use relays and pull headlight power straight from the batteries. it makes your lights brighter and less current through the switch
Logistics Pro
Joined: Jun 2009
Posts: 4,116
Likes: 6
From: metairie, LA
Trending Topics
More Turbo
Joined: Dec 2002
Posts: 664
Likes: 129
From: Columbia, MD
LMC Relay Harness
The LMC catalog has a relay harness for the OBS. It takes the high amp bulb current off the switch circuit. The switch circuit only sees low-amp relay control current. The headlight bulbs are fed from the relay in the harness, and the relay comes straight from the battery. This way, you don't burn up the switch and wiring.
The harness does the same thing as the DIY link. You should be able to get the DIY parts for less than the LMC harness, but the LMC harness has absolutely no splicing. For the LMC kit, you unplug both headlight connectors. Two harness plugs go onto the headlights, one harness plug goes onto one of the vehicle-side plugs. The other vehicle-side plug isn't used, tape a plastic bag over it. One wire on harness goes to battery positive, and I recollect one wire to chassis ground. And you're done. Zero cutting and splicing, and the harness is fairly cheap.
Whichever way you go, the relay approach takes the 10 amps / 120 watts that goes through the headlight switch and wiring in a stock setup down to a much lower level.
The harness does the same thing as the DIY link. You should be able to get the DIY parts for less than the LMC harness, but the LMC harness has absolutely no splicing. For the LMC kit, you unplug both headlight connectors. Two harness plugs go onto the headlights, one harness plug goes onto one of the vehicle-side plugs. The other vehicle-side plug isn't used, tape a plastic bag over it. One wire on harness goes to battery positive, and I recollect one wire to chassis ground. And you're done. Zero cutting and splicing, and the harness is fairly cheap.
Whichever way you go, the relay approach takes the 10 amps / 120 watts that goes through the headlight switch and wiring in a stock setup down to a much lower level.
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Thread Starter
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Tuned
Joined: Jul 2010
Posts: 344
Likes: 8
From: Kennedy, NY 14747
Hi Guys,
Thanks for the great info.
I just looked at the harness from LMC, $30.00 is a good price for a plug & play system. I think thats the way for me to go.
I know Mad Electric or something like that sells a kit for classic muscle cars.
I wonder why the factory did it this way? It seems the mod would have allowed them to use cheaper headlight switches, which may have been a wash for the relay cost. Who knows?
Thanks again,
Joe
Thanks for the great info.
I just looked at the harness from LMC, $30.00 is a good price for a plug & play system. I think thats the way for me to go.
I know Mad Electric or something like that sells a kit for classic muscle cars.
I wonder why the factory did it this way? It seems the mod would have allowed them to use cheaper headlight switches, which may have been a wash for the relay cost. Who knows?
Thanks again,
Joe
Fleet Mechanic
Joined: Aug 2007
Posts: 1,508
Likes: 2
From: The boonies by Dallas OR
I did mine a little different. I copied the "Japanese style" wiring. I ran a 20A fuse to each common terminal on the headlamp. The relays then ground out the high or low beam terminal.
The advantage to this style is that if you ever have a short, you only lose one headlamp.
The advantage to this style is that if you ever have a short, you only lose one headlamp.
FOREIGN GURU
Joined: Jul 2006
Posts: 7,655
Likes: 7
From: Celaya, Gto. MX
The LMC catalog has a relay harness for the OBS. It takes the high amp bulb current off the switch circuit. The switch circuit only sees low-amp relay control current. The headlight bulbs are fed from the relay in the harness, and the relay comes straight from the battery. This way, you don't burn up the switch and wiring.
The harness does the same thing as the DIY link. You should be able to get the DIY parts for less than the LMC harness, but the LMC harness has absolutely no splicing. For the LMC kit, you unplug both headlight connectors. Two harness plugs go onto the headlights, one harness plug goes onto one of the vehicle-side plugs. The other vehicle-side plug isn't used, tape a plastic bag over it. One wire on harness goes to battery positive, and I recollect one wire to chassis ground. And you're done. Zero cutting and splicing, and the harness is fairly cheap.
Whichever way you go, the relay approach takes the 10 amps / 120 watts that goes through the headlight switch and wiring in a stock setup down to a much lower level.
The harness does the same thing as the DIY link. You should be able to get the DIY parts for less than the LMC harness, but the LMC harness has absolutely no splicing. For the LMC kit, you unplug both headlight connectors. Two harness plugs go onto the headlights, one harness plug goes onto one of the vehicle-side plugs. The other vehicle-side plug isn't used, tape a plastic bag over it. One wire on harness goes to battery positive, and I recollect one wire to chassis ground. And you're done. Zero cutting and splicing, and the harness is fairly cheap.
Whichever way you go, the relay approach takes the 10 amps / 120 watts that goes through the headlight switch and wiring in a stock setup down to a much lower level.
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