How To Tell If 2008 GMC Sierra 1500 May Have Had Trailer Brake Controller Installed At One Time

Question:

Ive seen videos on how to install a trailer brake on my truck, and all of them end with connecting the 2 red wires under the hood to the power posts under the black cover on the fuse box. Well I dont have a trailer brake installed, but both of them red wires are already hooked up. Is it possible the owner before me had one and took it with him....and also, there is a empty plug directly above my emergency brake on the wall to the left....could this be a quick connect?

asked by: Michael P

Expert Reply:

It is possible that the previous owner of your 2008 GMC Sierra 1500 SLE had a trailer brake controller installed but removed it when they sold the truck. If this is the case there should be some screw holes in the plastic of the dash somewhere where they would have mounted the controller.

Now since your Sierra didn't have a factory port and has wires there would not be a port on the wall, but could be a harness attached to the factory wires for plugging a trailer brake controller in if the previous owner left it. You would see wires with butt connectors connecting it to a roughly 12" long harness, and at the end of that harness would be the connector.

If you do not have this and still just have the factory wires under the dash that is no big deal. You can still easily install the Tekonsha Voyager # 39510 by using pigtail harness # 20127 and the included butt connectors to make the connections to the factory wires. Since you mentioned the two red wires in the engine bay are already installed then you are already set in that regard.

I included a video of the Tekonsha # 90885 being installed in a 2008 GMC Sierra 1500 to show you exactly which wiring connections you will need to make as it will be the exact same as your # 39510.