Heres what I want to do For back up lights.
2 - 18w leds under the back of truck
2 - 2w Rock lights( one in each rear wheel well)
All hooked up to the reverse light..
Would 54w be too much?
Ok ,I'm not done yet
Also I want to put the exact same setup on my trailers(utility , enclosed,and dump trailers) Hooked up thru the 7 pin harness. So when in reverse Ill have @ 80w running
Is this doable ?

 

Did I ask in the wrong section

 

As long as you use the proper relays and wire gauge, you'll be fine. I wouldn't hook anything directly to the reverse light wire without a fuse and relay.

 

ak is correct. You should not be drawing power from the reverse lights, they should only be the trigger for your lights. Your lights should draw power from a fused connection to the battery or other dedicated power source.

 

Using the reverse circuit from your trailer harness directly is fine. It is operated by a fuse and relay. You should be able to use it for your 80W (80W / 12V = 7A).

 

Thank you all. I will be pulling off the 7 pin.
I had to take one of the trailers in for some warranty work and asked them what it would cost to just run the wire on the trailer.no lights just the wire . They wanted $300 ( which I thought was nuts but ?)
.The trailer already has the 7 wire connector
I know its the center pin and I see the purple wire.
I found a 2 leg wire harness with 40amp relay for $15 on amazon.
wire loom $5.

couple quick disconnects $10
I cant see it taking me (whos never done it before) more then an hour maybe hour and a half.
I dont like doing 12v work but for $250 an hour ,,,i'm all in