Short background: I installed a set of Hella 500's on a car that didn't have fogs to begin with. I decided to follow the directions that came with the lamps. It didn't work. I just burnt up a wire (now repaired) and wasted my time.

So...I bought an OE switch and connected the lights to the wires already in the car.

Connections:
Black wire on lamps to the yellow and white wires from the car.
Blue wires on lamp (ground) to brown ground.

K on switch to gray/red.
31 on switch to brown ground.
15 on switch to brown/blue

on the CB panel I see the red/black, gray/red, white/blue, and white/yellow wires taped together and go under a black relay.

I'm assuming all is good. But when I turn on the lights and pull the fog light switch, the lights dim momentarily and then "snap", the CB pops.

What am I missing? Do I need to install the relay that came with the lights? I'm so bad with electronics, I don't even know where to start. Except that I checked and cleaned all grounds. I checked and traced all wires - no issues.

As I understand it, the relay is to transfer a larger load from a direct battery source with a lower switch rated source!

So, you should run a larger red wire from a larger + source to the relay and use the switch to make the connection (through the relay) to the Ground which would go to the chassis to light the new lights!

All wires from the relay to the lights would need to be rated to the amp load of the lights as well as the + to the relay directly from the battery or large source. The ground wire to the light should be the same size as the larger + wire now installed!

The two wires from the switch just trigger the relay to transfer the + from the relay to the light which is grounded.

Yes, Jeff got it right. I ran big ol' 10 ga wire from the battery up to the front to a relay that is powered on/off by the switch. I did this for my stereo too (although I never turn the thing on- I couldn't hear it anyway ).

Hey- I've been to Anecortes. Some fun driving up around there....

OK, I think I understand what you guys are saying....

I need to run a new 10 or 12 guage wire (the Hella supplied wires are 16 guage so I think I'm safe with the 914's 12 ga. wires) from the battery to the 30 terminal on the new relay. Yes?

The 85 terminal on the relay is connected to the K terminal on the switch. I can use a new wire or the one on the harness.

The switch is grounded on 31 and the 15 terminal with the brown/blue wire I leave alone.

Then I re-route the 87 terminal (white/yellow) and the 86 terminal (white/blue) to the new relay.

Correct?

Oh and yes great driving up here. My commute to work is down the west side of the island through all the twisties. Eight miles, two stop signs and one light.

OK, same story different day.

I routed a wire directly from the battery to terminal 30 on the new relay. I installed a CB in that wire.

I wired the rest up, turned on the lights and pulled the fog switch. The CB on the wire popped. It's a 25 amp CB.

What's wrong? Too much juice?

Edit: I double-checked everything. And just to be sure, I disassembled the lamps. Bingo. The wires were completely wrong from the generic instructions sent with the lights. Quick swap and I'm in business.

Yaaaay!

always check the pysical layer...


I like this site for wiring lights: Susquehanna Motorsports Free diagrams and a little note that wire is heavy!

Check it out...