I used to have a 1999 GMC Sierra and with my trailer hooked up I never had this problem. All the lights worked perfectly. Now with my 2002 Chevy 1500HD, when I hooked up my trailer lights to the rear receptacle, after a couple of miles my parking light fuse blows out. The fuse is the one under the hood and is rated at 20amps. I heard that this was a common problem, but I doubt it. Is there any troubleshooting ideas you guys can give me? I dread driving at night and having those lights go out. My stop/brake lights still function. Also the parking lights on my truck will still function as well, they will not blow a fuse, only the trailer parking light fuse will blow.

 

I had this to happened to me and found out the trailer was wired wrong. After rewiring the trailer connector the lights work fine, no more blown fuses.

Look at the wiring of the trailer connector and truck connector, either one could be wired wrong.

 

Here is a good website on wiring the trailer and truck connector.

Trailer Wiring

 

trailer and truck lights are on seperate fuses, sounds like a chaffed wire on trailer grounding out and blowing fuse, check trailer wires for frayed wire,

 

That's just it, on my 1999 Sierra I had no such problems. I pulled this same trailer for about a year and it never blew a fuse with the Sierra. Both trucks have the Tow Package. This 2002 1500HD did have a camper shell from the previous owner, and I think he may have f'ed something up. The trailer's wiring is fine, I think it is in the trucks harness somewhere. I am just going to have to go through this beast and check the harness with my voltmeter.