Sponsors

flawlesslydisturbed · 03-01-2010, 07:48 AM

I'm getting ready to hook up four 55 watt fog lights and was wondering if I should use a relay.
I didn't get a wiring harness with them so I'm not sure if there is a certain type of relay I should use or even what amp fuse to use.
Any ideas? I'm not electrically inclined.

flawlesslydisturbed · 03-01-2010, 10:51 AM

bump

4.3L XJ · 03-01-2010, 11:25 AM

You have 220 watts total lighting which comes out to a little more than 18 amps. Some switches are rated for 20 amps, but that would be pushing it. The switch would eventually fail. You should put in a relay. You can get a standard relay with a plug that already has wires attached at a good auto parts store.

flawlesslydisturbed · 03-01-2010, 11:48 AM

I was lookin around and found a 30 amp relay and a switch rated for 30 amps but I'm not sure how to hook the relay up.

flawlesslydisturbed · 03-01-2010, 11:50 AM

Thanks for the input 4.3, I was hopin you would chime in. I think I'll try the auto parts store.

**CT99XJ** · 03-01-2010, 12:01 PM

definitely use a relay man, i know Jerman75 would have an aneurysm otherwise

the relay pulls all the current out of the switch, so all the switch does is trip the relay to activate the lights. the relay should be wired to the positive of the lights, the master positive (i.e. battery- make sure to fuse it!!), a ground, and the switch. the switch then needs to be grounded as well. essentially what the switch does is lift and drop a ground to complete the circuit for the relay.

flawlesslydisturbed · 03-01-2010, 02:37 PM

Found a 40 amp relay with a diagram so I know what wire goes where.

Thanks for the relay lesson guys I appreciate it.

4.3L XJ · 03-01-2010, 05:47 PM

Cool. If you have questions, don't hesitate to ask. Use #12 wire off the relay. It is rated for 20 amps. You can divide it or depending on the relay you can run two, one for each pair.

tbone · 03-01-2010, 06:20 PM

There is a diagram of the way to wire up your lights with relays about half way down the page and there is a lot of good info here. Hope this helps.
Automotive Wiring Tips

**CT99XJ** · 03-01-2010, 06:40 PM

Is this for your roof light setup? On my light bar, i ran left/right pairs to separate relays but the same switch.

jerman75 · 03-01-2010, 07:15 PM

JRW7072009 · 03-03-2010, 11:35 AM

Just throwing this out there Pro Comp has a universal light wire kit they some in singles and doubles. They go for about $13-25 they come with a 30-40 amp relay, wire, and a switch.

Here is a pic at the bottom of the page.
Pro Comp Suspension Systems

flawlesslydisturbed · 03-09-2010, 08:49 PM

Thanks guys.
I found a 40 amp relay and ran all the wiring and hooked everything up and hit the switch......nothing!
I forgot to run a 12v constant to the switch. oops!
Hooked one up and now I light up the night.

4.3L XJ · 03-09-2010, 08:56 PM

jerman75 · 03-09-2010, 09:00 PM

put a 3 to 5 amp fuse between the 12v and the switch you hooked up too. always use a fuse on any connection to power as close to the connection you can. Fuses are intended more to protect your vehicle from overheated, melted, burning, OH-MY-GOD-MY-JEEPS-ON-FIRE! situations than it is to protect to component(s) actually using the power.