So i just finished installing a new JCR front bumper. I rewired in new fog lights to the old wiring that was there (spliced in the new lights to the connectors for the fog lights). I did a test, and they worked with the switch yesterday and everything was fine, both turned on and off with the switch and with highbeams.

Today, i installed them on the bumper and installed the bumper, plugging in the connectors and went to test. For reasons unknown to me, the lights wouldnt turn on. All fuses are good, and i'm pretty sure the relays work, but unsure of how to check. The lights are good, i tested them, and i'm getting a reading of 0 volts at the connection. I did unplug the battery without the fog lights attached, and plugged reconnected it (the switch for the fog lights was on). My only thought is to turn off the switch, reconnect the lights. unplug and replug in battery. Anyone have any other idea what the problem could be?

Check your grounds on the lights???

yeap sounds like a ground. pull them off and clean the surface then replace.

I didnt specifically check the grounds. I put the lights straight to the battery and they both it up, so I would assume the grounds on the light are fine (they ground through the wiring system, just like the stockers).

My only guess was that something funky happened when the switch was on, the lights were not attached and the battery was reinstalled.

And ivie, is there a specific area for the fog lights? My understanding of the wiring had everything run into the harness and connect, and with the lights working correctly before disconnecting the battery, I assumed that i had them wired correctly.

x2

I am not sure from your post if these lights are aftermarket lights or stock lights but I am going to take a shot and guess they are aftermarket from the way you tested them. If they are aftermarket you spliced them into the existing wiring then you need to make sure that you used the black stock wire as the hot power wire (connect to your red wire on new lamps) and your blue stock wire is your ground. If you did not connect them like this then you have found your problem. Let me know if that is your issue.

splice in a second ground wire and ground to new bumper

I still dont have power to the connector that is on the jeep though. The female adapter had a zero voltage reading, so I assumed that the problem was something with the jeep wiring.

well you could always do a continuity test to set this grounding concern to rest. It might be the switch though. I've researched our factory switch to death, since mine wasn't equipped with one, and there is some unique wiring going on here. The total wattage pulled from the lights is traveling through the switch and when paired with higher wattage offroad lights, it can melt some of the switch as the contacts heat up.

are you checking using both wires or grounding to the battery

I think that did the trick. I had the fuse for the fog light relay under the hood blow, and with them wired as above it works. Thanks for all your help.

Good deal, never understood that black wire being the hot wire because the universal ground wire color is always black. You would have thought they would realize the potential problems that would have caused. Glad you were able to get it working.

Yep, I even checked with a volt meter to make sure i wired it correctly. Apparently the EE in me took over, and I made an assumption after i already tested it. And maybe that's where all the electrical gremlins come from within the jeep, maybe even they got it messed up every once and awhile.. ha ha