I just wanted to share something that I have come up with. We all know that the headlight harnesses get moisture and corrode, especially where the harness connector connects to the body wiring connector(the black 5 pin, 6 hole connector). I'm sure a lot of users on here have opened them up and found the inside all green, chalky, blue, whatever it may be but just corroded. Maybe have you have experienced problems where you have had to physically hit your headlight to get it to turn on. For the most part I think we have become accustomed to just cleaning the connector and running it until it happens again...which it will. A few of us, like myself, have even had to replace broken pins because they have broken.

Moisture gets in the connector because these are a 6 wire connector, however, they only have 5 pins. Sure there is a seal that runs around the outer edge of the body harness connector but even that has 6 holes with only 5 pins. Moisture and water can, and usually does, find a way into the connector and its through the 6th pin hole. There is a simple solution.

First make sure that if you have not already you clean the connector. There is electrical cleaner but ammonia and water or baking soda and water will work too. Once all of the corrosion is gone take a sealant, clear or black weatherproof caulk will work perfectly, and dab a little in the empty hole from the wire side of each connector. This will ensure that it stays sealed and should prolong pin life providing the weather seal is good. Also, you can use dielectric grease on the inside of the connector for added conductivity.

 

I have this problem, I used the harness that came with my aftermarket lights. Big mistake. Water got in the connector, pretty much destroyed that and the wiring harness for the front end. One side headlight/signal isn't working and the opposite side fog light is out.
Been waiting over a week for the main harness from GM, the ones attached to the headlights have been discontinued, luckily I still had them on my stock lights. Needless to say, all the connectors will be properly sealed and greased when it gets fixed. Good advice.

 

Thanks. I'm rebuilding my friends connectors but the pins are discontinued. I found enough from the surrounding dealers but I was planning on stocking up. Since I couldn't I decided to figure out a way to seal them properly. I don't know why they didn't just leave the one pin hole solid but that's classic engineering.

 

probably because they dont make the connectors they buy them from company X