Trailer Power

FstBlkBrd · February 7, 2008

Hi !

Can anyone point me in the right direction as to how I can get power through my 7 way connector on the truck to feed the trailer. On my last 01 Silverado 2500HD I had to install a fuse into the underhood box. I looked in my new owner's manual for my 08 Sierra 2500HD and where the fuse I thought I'd need, there already was one 40A fuse in the slot. ( slot 68) I'm gonna continue to look through the book and the fust panel, just wanted to know if any one else bumped into this yet. Thanks !

Chris.

2008 Sierra 2500HD Duramax. - First diesel and loving it !

ABQFirefighter · February 7, 2008

Is the wire hooked up to your fuse box? These trucks do not have them hooked up from the factory. Look down into your engine from the driver's side. Look below the master cylinder and you should see a coiled up red wire that is zip-tied. Connect that to the stud at the front of your fuse box. You have to supply the nut, 7 or 8mm if I remember right. That will give you power to the plug, as the fuse is already in place.

FstBlkBrd · February 7, 2008

Thanks for the help, you nailed it. Right where you said it would be. Looks like we have the same taste in trucks, I just traded in my 2001 Silverado with the 8.1 for a new LMM CCLB. Pictures to follow. Take it easy.

Chris.

msatow · February 8, 2008

Really,, thanks a lot. I looked all over for the D*# fuse to install. Now I know I'm not nuts.

bensrudy · February 10, 2008

I was looking at my truck today and the wire isn't tooked up. But I am confused on which stud it should be tooked to. There is two on my fuse block, one has a wire hooked up with a nut on it and the other doesn't have anything on it?

whmayhew · February 10, 2008

There are two wires, one for the brake controller, one for the battery on your trailer. SinisterSS has a detailed instruction of how to do it. I forget how to find it but it is Document # 1866253. You can also go onto the PPL Motor Homes web site and download the instructions for the NBS. It does not seem that hard. I ordered a new Prodigy yesterday and when it comes I will do my install.

caleald · March 13, 2008

Does wiring solution apply to an 05 Sierra 2500HD Diesel with dual batteries?

Ranger · March 13, 2008

No, you're already pre-wired and have a port to plug into under your dash, just need the fuse installed.

caleald · March 13, 2008

No, you're already pre-wired and have a port to plug into under your dash, just need the fuse installed.

I hooked up the brake controller, plugged in the factory harness under the dash, and installed the 30A fuse that came with the harness. Brake controller works fine. The trailer battery charge wire at the trailer plug is not hot. Do I need to install another fuse somewhere?

BlackSilver · March 13, 2008

I was looking at my truck today and the wire isn't tooked up. But I am confused on which stud it should be tooked to. There is two on my fuse block, one has a wire hooked up with a nut on it and the other doesn't have anything on it?

Below is a photo of the fuse center (cover removed), taken from the front of the truck looking toward the firewall.

The right-hand stud (shown with two wires attached) is the proper stud. The wire is red with a light blue tracer, and a tag/label with words like "after market trailer power" or something like that.

(No, I don't know what the other wires do...... probably related to the factory integrated brake controller.)

Ranger · March 14, 2008

Little side note, I looked in my engine bay and the wiring harness was located next to the fuse box on the fenderwell, not under the brake master cylinder

caleald · March 14, 2008

Little side note, I looked in my engine bay and the wiring harness was located next to the fuse box on the fenderwell, not under the brake master cylinder

Thanks Ranger...I'll look and update the post on what I find.

caleald · March 15, 2008

Update to trailer battery power.

There is a 7 pin plug attached to the frame above the spare tire. It appears this plug connects the wiring from the fuse box to the rear trailer plug and the fifth wheel trailer plug. I unplugged the connector and discovered the problem. The male spade connector inside the plug (for trailer battery power) was appearently bent over when the connector was plugged in at the factory. Must have been assembled on a Friday at quitting time! It's fixed now.