Brake Controller Adapters

kendamn · April 13, 2009

I have searched and can't find if there is a brake controller adapter that plugs in under dash like my '04 did for the 2008 Sierra? I have the tow package but not the factory controler.

Thanks

jwstewar · April 13, 2009

I have searched and can't find if there is a brake controller adapter that plugs in under dash like my '04 did for the 2008 Sierra? I have the tow package but not the factory controler.

Thanks

Starting with the new '07 body styles you don't do the plug-in harness like you did on the previous generations. There is a group of 4 wires up under the dash that you will have to pull down and direct wire your brake controller in to. I just did this with my Suburban.

Here is one set of instructions: etrailer Here are the directions that I used to install mine: stealthrv

c4cruiser · April 13, 2009

I have searched and can't find if there is a brake controller adapter that plugs in under dash like my '04 did for the 2008 Sierra? I have the tow package but not the factory controler.

Thanks

Starting with the new '07 body styles you don't do the plug-in harness like you did on the previous generations. There is a group of 4 wires up under the dash that you will have to pull down and direct wire your brake controller in to. I just did this with my Suburban.

Here is one set of instructions: etrailer Here are the directions that I used to install mine: stealthrv

It seems stupid that GM stopped using a plug for a trailer brake controller harness but at least the wires are still there. With the earlier trucks that came with a towing package GM gave you a harness with the plug on one end and a fuse for the 12v power lead.

My 08 came with the factory controller so I didn't have to do anything. But I had to go buy the 12v fuse. That's pretty cheap on the part of GM.

jwstewar · April 13, 2009

One of the problems with the harness was people losing them. When I bought my truck new (I ordered it), it wasn't with my truck. I picked it up 2 hours after it came in on the truck. Dealership had to find me one as I was planning on hooking a brake controller up the next day. The other thing is buying a used truck. Typically the previous owner wouldn't leave them in the glovebox, so then you had to order one. Actually it was a 2 step process before. 1.) Wire the harness to the controller 2.) Plug the harness into the fuse box under the dash (and there were 2 it would fit) so you had to figure out which one. So all in all, I don't see where this way is any worse or any better. A little harder to hook the wires up because you have to do it in the vehicle, but at least you don't have to go buy a harness after it gets lost.

kendamn · April 13, 2009

Thanks. I can't believe I have to connect wires under the hood. This truck has been a real step backward from the '03 and '04 models that I have owned.

c4cruiser · April 13, 2009

One of the problems with the harness was people losing them. When I bought my truck new (I ordered it), it wasn't with my truck. I picked it up 2 hours after it came in on the truck. Dealership had to find me one as I was planning on hooking a brake controller up the next day. The other thing is buying a used truck. Typically the previous owner wouldn't leave them in the glovebox, so then you had to order one. Actually it was a 2 step process before. 1.) Wire the harness to the controller 2.) Plug the harness into the fuse box under the dash (and there were 2 it would fit) so you had to figure out which one. So all in all, I don't see where this way is any worse or any better. A little harder to hook the wires up because you have to do it in the vehicle, but at least you don't have to go buy a harness after it gets lost.

When I bought my '99 from the local dealer, the harness was in the glove box. Typically, when a PDI is done on new trucks that had the tow package, there is a checkoff item for the harness.

I had bought a Prodigy controller and I wound up splicing the truck harness to the Prodigy harness so I was able to do that inside. With the Tekonsha controllers, they offer a complete harness for GM, Ford, Dodge, and Toyota trucks that have the prpper connectors at both ends. I didn't know about them at the time otherwise I would have ordered one. For the 99 it was all of $11.99.