bwFX42006

Okay, I know I've posted a lot about fog lights and lighting lately, but I need some education. I was hoping someone could give me a little more insight on wiring in relays, and harnesses, etc.

Above is my truck. For extra lighting, all I have currently is a pair of Rigid Industries D2 fog lights mounted to my bullbar. I have them wired to the battery then the switch in my dash, the whole system was plug and play, or direct connect to the battery. I plan on adding more lights, maybe behind the grille, or adding an additional light bar somewhere. What is the best way to wire all this in to the trucks electrical system? I'm pretty mechanically inclined, but do not have much experience with electrical work. I want to be able to control the lights from cab switches, and I know I need to install a relay so I don't have a million wires running to the battery from several different lights.

Also, I may install the light bar directly to the top of my back rack, it has several mounting locations. What would be the best way to wire it to the battery? Under the cab? Any insight or direction would be greatly appreciated. I never realized how addicting lighting is. MUST HAVE MORE LIGHT!!!

ford4wd08

You need to run relays. Even though led's don't use much current, you'll want the relay to carry all of the current in the system. The switch will only be used to trigger the relay to on or off. Just look on web, many wiring diagrams out there for them.

bwFX42006

So basically the relay carries a majority of the load so the switch doesn't burn out?

ford4wd08

Edit* actually it carries all of the current for the light circuit. The only current going through the switch will be the amount to trigger the relay. The relay is basically like a switch that is trigger by a smaller curcuit.

bwFX42006

Okay, I understand. Now should I put my Rigid Cubes on a relay. They don't pull much load anyway...I think like 1.5 amps each...so i figured i could just leave them direct wired to the battery and then run my next set of lights on a relay.

Mod (Ret.)

Typical relay wiring for lights. Notice that even with a relay, you still want to have a fuse inline with the power lead that "feeds" the relay:

bwFX42006

Very helpful diagram. Is it necessary to have a relay for each set of lights? Meaning only two lights per relay?

brantlyj

I would each group of lights on it's own relay. So if switch one operates lights 1 and 2, that would have it's own relay. switch 2 operating lights 3 and 4 would have another relay, etc.


Also you can get a power distribution bar so you don't have a million wires going to the battery.

bwFX42006

Something like this?

brantlyj

Yup!