lmc HD headlight harness gmc/4 lights

[chalet2506]

Originally Posted by GMCJOE

So you are saying just on the headlight side of the LMC harness you have to match up the wires to the factory harness? Nothing else required at the relay's or where you plug the power side of the factory harness into the LMC harness?

I changed the headlight plugs and the plug that connects to the factory wire harness.

The upside about having to deal with this is I now have a pretty good idea how the headlight system works. If there are any more problems down the road I'll just toss the lmc harness and build my own.

Might end up doing that anyway, having all the original headlight plugs and wires hanging around looks kind of junky.

[GMCJOE]

Thanks.. I figured if you did the head light connectors, the harness end would have to be done too. I figured they had at least wired the relay's right, since they will only work right in one configuration. I understand the principles off electricity, but I hate dealing with it cause I still haven't quite got down wiring up relay's yet. And being a mechanic in the Army, they have trained me on it a couple times. Mostly on trouble shooting a electrical system with relay's, and one class building a high beam low beam light system on a electrical board. Talk about sucking something fierce at it...lol Understanding the concept of a relay isn't hard though.

I bought C5Phil's extra LMC HD Light harness for my future switch to the H5 headlights on my GMC, figured it would save me a few dollars and get some hands on electrical training again.

And I very seriously doubt LMC will correct this issue, considering they purchase the product from someone else. To them it's not the product that has an issue. Maybe if enough people complain that purchase it, they will find another company to go thru. So far I haven't had any issues with anything I have purchase thru them.

[DDassow01]

I know this is an old thread but it helped me with the LMC HD Headlight wiring harness on my 70 GMC. It is still wired wrong but I was able to remove the connections from the wiring harness sockets and match them up with the factory wiring and it worked just fine. Here is the harness as it came from LMC...

[DDassow01]

And here is how it should be wired. There is also a picture of the low beam connection that had to be modified on both sides to match up with how the factory wiring was. Kind of a pain to have to modify something new out the box but once done it works great and looks good. Lights are noticeably brighter now.