I've been running Hella 500's on my 1996 XJ for a while now. I've been using all of their wiring and the cheap green switch that came with the kit (that never lit up like it was supposed to). The Hella relay blew after just a few months, so I replaced it with a new one from the local auto part store and all has been well.



I decided to go for an OEM look and bought a fog light panel out of another XJ at the junkyard and ordered a new, OEM fog light switch for it.



Both the OEM switch and the Hella switch have three prongs, so I though it would be an easy swap. After doing a ton of searching, I wired up the new switch, but it must not have been correct. The yellow light on the switch was constantly on and flipping the switch did not turn on the Hellas. I unplugged it, reconnected the Hella switch, and now that doesn't turn the lights on, either. Now I can't get them to come on at all.

Here's the Hella switch, with its three prongs:



The Hella wires are supposed to be set up like this, from top to bottom:

Yellow - to relay under the hood
Green - constant 12V power (plugged into the fuse box under the dash)
Blue - ground

When I initially hooked up the OEM switch, my forum sleuthing had me hook them up like this, from top to bottom:

Green
Yellow
Blue

Like I said, that kept the yellow light on indefinitely and the switch didn't turn on the lights. I believe it should have been wired just like the Hella switch, so I hooked it up like so:



Now the yellow light won't turn on and neither will the Hellas. I was worried that I fried the switch, so I plugged the Hella switch back in, just like it was working earlier, and nothing happens. No lights. I checked the inline fuse and it was fine, but I replaced it anyway. I replaced the relay with a new one and that also didn't do anything. So in other words, I completely reverted everything back to how it was, when it was working fine, and nothing works anymore. The copper from the yellow wire that leads back to the relay looked just a tiny bit dark, like it had seen some heat, but it doesn't look burned at any point on the yellow casing.



Nothing looks out of the ordinary. No melting, bubbling, or obvious signs of a short. All of the wires look fine. All of the connections look solid. All fuses are intact. NO LIGHTS. What the hell is going on?

 

Same switches same lights over 2 yrs zero issues. If the switch didn't light up you should have found the problem then.

 

do you have a multi meter? if so you need to start checking voltage from your 12v source......also just a habit, I always double check the connections/battery terminals make sure nothing is loose. A loose connection can cause havoc, especially if it is making/not making on and off. I had a loose ground connection once that caused all kinds of weird stuff.

 

also double check your wiring to the relay. if the light on the switch was constantly lit something was off. if you have a wiring schematic from hella post the link or the schematic.

 

So I'm an idiot. I forgot there was an inline fuse on the green wire. I went out and checked it. Lo and behold, the puny 2 amp inline fuse is blown. There's my issue. I need to take the dash apart again this weekend, so I can replace some bulbs. I'll give the switch another try when I do that and I'll report back with the results.

 

Glad you found it buddy, see if you can find what caused it to blow if you can don't be tempted to just cram a larger fuse into the line.

 

Yeah, I've been reading like crazy about the factory wiring to the fog light switch. I think I have the right order for the wires, now (ground, power, relay). I'm going to put the wires in the correct order before I replace the fuse and try the switch again.

 

Good luck.

 

The wiring that comes with the Hellas is terrible. It's a must to upgrade to some good quality 14 gauge wire.

 

Yeah, the Hella wiring, switch, and relay are all pretty craptastic. I love the lights themselves, but everything else in the kit left me a little disappointed.

So I rewired the OEM switch (from top to bottom):

Blue (ground)
Green (12V power)
Yellow (to relay for fogs)

Then I replaced the fuse on the Hella green wire, flipped the switch, and...they work! The light on the switch functions as it should, too. So I now have Hella 500's wired up to a factory switch. No more little green buttons that don't match a thing. I love the OEM look and despite a couple of headaches, I'm stoked about how it finally came out.