Fog Light Gremlins

Back when I first got the XJ I wired my 55W Hella 500's into the factory fog-light wiring so I could use the factory switch. That worked great for about three months. Now when I try to turn them on they'll stay on for only a couple of seconds then off again. If I wiggle the switch and hold it in the on position, but a few millimeters above the place where it normall rests when "on" the lights will stay on.
They have ground and power, as there are no breaks or corrosion in the wires...think I just need a new switch? Are these factory foglight switches prone to failure?

i had my kc's hooked up to mine for a while, and the switch would get really hot, i think the problem is too much power draw, and it might have melted something... i ended up installing a regular rocker switch on mine cause the heat thing scared me.

I have the same 55w Hella's on my 98, I've read it's not a good idea to use the factory driving light wiring and switch because the Hella's push to much current.
Anyway that's my guess, I used the switch and harness that came with the kit and followed the instructions, installed last Sept. and have had no problems.

Sounds like you need a new switch, probably burned out from too much draw. I have got two 100w KC lights running off my factory switch. The best way to do it is to have the wire coming from the switch activate a relay to power the lights. Veryt small amount of amps will be going thru the switch that way. Let the relay handle the power. Use a 30-40 amp relay with a 20 or 25 amp inline fuse for the power supply to the lights.

I run 4 100 watt lamps through 2 relays. I don't have OEM fogs, but I wouldn't use OEM switches as they are designed to run a max of 60watts IIRC.

It takes less than 5 amps to activate a relay. Your factory switch is more than enough to do this. DO NOT run full power to the lights thru the switch.

LoL. Im not a newbie to wiring up lights but it was quick and easy to run them to the factory switch, and the switch is run to a relay. Maybe I'll rig something up to use the switch but power my own relay....