My partner was going to tow my boat but when we plugged in to his 3/4 ton silverado, no trailer lights! He plugged it in when he had his motor running and lights on and I think that's when he blew a fuse. Anybody know which fuse it is, and is it located inside the truck or in the engine compartment? Nothing is labeled to indicate the main fuse for the trailer (all lights were out).

(We ended up using my truck (1/2 T Silverado) and all trailer lights worked.)