Wiring Help

[Steve_m]

I am looking to install some lights on the back of my truck and I need a little bit of help with the wiring. I want them to come on with a switch that i will mount in the cab, but I want it to be on accessory power so I can't leave them on when the truck is off. So if the two lights are 55Watts each, that would mean that I would need to tap into atleast a 10 amp fuse right? (5 amps for each light). Or would a 15 amp be better? Also, I would need a relay and I know nothing about these. Could someone help me with how to wire the relay in? Thanks.

[dsmazz]

Here's a file that should help. The line with the diode and the connection to factory backup lights is optional.

[ScottyBoy]

Mazz beat me to it, he hit the nail on the head.