Hey guys, when I connected my trailers electric brake controller the pigtail in the glove box came with a 40A fuse. It said to plug the fuse in the fuse box under the hood in the stud #1 space. When I looked at mine it already had a 50A fuse in this location. Are you supposed to remove the 50A and install the 40A or just leave it in.


Thanks for the help.

04.5 lly 2500hd cc 4x4

Usually stud 1 has a shunt. You better leave it at 50amp just in case you have the wrong fuse.

Are you looking at the fuse that is on the very front and to the extreme right of the truck? In other words front passenger side fuse?

Yes Max, Thats the one i'm looking at. It's under the white sticker thats in the fuse box. When I pulled the paper up it already had a 50A fuse in it.

Thanks,
Jason

If you look at the white tag that was on the jumper set up that came in the glove box, the last few lines say:

4: Do only one of the following:
1) For vehicles without the TP2 option ( auxilliary battery ) plug in the 40A B+ trailering J-case fuse in the stud #1 location of the UH electrical center.
2) For vehicles with the TP2 option ( auxilliary battery ): discard the 40A B+ trailering J-case fuse- it is not needed.

Reason I know, I just hooked up my brake controler.
Pete

the 40A fuse is required for a diesel, not for a gasser, I believe because the diesel uses both batteries such as starting, not just for accessories. pretty sure you need fuses in stud 1 and 2 locations

yes, you need the fuse it completes the circuit so you have a constant HOT to charge your trailer batteries.

Donnie 1 is correct. I just went through hell on a trip from NC. to CA. because the dealer removed the 40a fuse from the #1 post. Had no clue as to why the trailer batteries would not charge.

Donnie 1 is correct. I just went through hell on a trip from NC. to CA. because the dealer removed the 40a fuse from the #1 post. Had no clue as to why the trailer batteries would not charge.
Similar thing happend on my new '05. My '04 Denali XL had the 40 amp fuse in the Stud 1 holder (and also one taped the the brake controller harness). I forgot to check the Sierra when I put in the brake controller. On the first trip with the new rig, I ran the trailer batteries down too low to start the Onan. No problem I figure, I'll just hook it up to the truck, and in 15-30 min. (maybe sooner) it will back feed enough juice to start the generator. No fuse = no power to trailer.

Interesting that jslamana had a 50 amp fuse mounted under the white sticker... it should be a 40 and is what I'd put in.