No Power To Trailer Connection

[sierra693]

I have a 2004 gmc sierra 1500 and i can't get any power to the 7 pin connecter. What happened was i bought the truck used and the guy broke off the mount for the stock 7 pin connecter so it rotted all the pins and i had to change it. I bought an aftermarket connector that matchs up to the existing harness under the bumper, installed it and had got it to work except for everytime i hit the brake or turn signals the trailer ligths would get very bright. After not messing with it for a few weeks i tryed it again the other day and now nothing works. I checked every fuse( there all good and have power), the two red wires are hooked to the studs on the fuse block as well as the blue wires and the 30 amp fuse is in stud number 2. Stud number 1 has the dummy fuse in it but from what i'm reading i don't think thats my problem because that 40amp seems to power accessories in a trailer but the trailers i pull don't need power for anything but the lights. All the light on the truck work and the truck came with the trailer package from the factory( tow/haul, hitch and trailer light connection,trans cooler). Any help/advise would be much great, thanks.

[ss502gmc]

I have a 2004 gmc sierra 1500 and i can't get any power to the 7 pin connecter. What happened was i bought the truck used and the guy broke off the mount for the stock 7 pin connecter so it rotted all the pins and i had to change it. I bought an aftermarket connector that matchs up to the existing harness under the bumper, installed it and had got it to work except for everytime i hit the brake or turn signals the trailer ligths would get very bright. After not messing with it for a few weeks i tryed it again the other day and now nothing works. I checked every fuse( there all good and have power), the two red wires are hooked to the studs on the fuse block as well as the blue wires and the 30 amp fuse is in stud number 2. Stud number 1 has the dummy fuse in it but from what i'm reading i don't think thats my problem because that 40amp seems to power accessories in a trailer but the trailers i pull don't need power for anything but the lights. All the light on the truck work and the truck came with the trailer package from the factory( tow/haul, hitch and trailer light connection,trans cooler). Any help/advise would be much great, thanks.

Seems like a ground problem to me which is the biggest culprit in all trailer wiring issues.