Well I finally got the last set of lights for my light bar, Now just have to wire them all up. Does anybody have any idea what size relay and wire I should run to hook up all 4 lights on the bar to one switch? I am also thinking about a small set under the bar to use as bed lights. I want to run the wires for that possabilty while I an doing the 4 main lights. I also want to do a quick disconnect in the bed incase I need to remove the bar and toneau cover for any reason. OK on to the pics....

 

Sweet lookin' truck!

To figure out the amperage capacity of the relay you need use the following electrical formula:

I=P/E

I is current. E is voltage. P is watts.

Add the watts for each bulb, for example if you have 4 one hundred watt lights, 400 divided by 12 is just over 33 amps.

If you are approaching this current level, use a MINIMUM of 12 gage wiring. I would personally use 10 gage for a safety buffer. Overkill doesn't hurt when it comes to current carrying capacity.

Wire your switch to the relay coil. You can use 18 or 20 gage wire for this since a relay draws very little current. Wire the lights through the relay contacts to a fused source. Never go without the fuse unless you're a firefighter...

Hope this helps!

 

Thanks that helps alot.

 

I have two 40 amp relays for my 2 pairs of Hellas. I also did 12 gauge wiring.