Trailer Lights Work, No Trailer Brakes And No Power At 7 Way Brake Pin Connector On 2001 Chevy 2500

Updated 07/26/2010 | Published 07/21/2010

Question:

My 2001 2500HD has developed a problem with the trailer brakes. All trailer lights work. The brakes do not work. I have a 7 pin connector in which the controller pin has no current. Tekonsha Envoy data indicates the brake pin should carry about 2a continually to act as a detection circuit for when the trailer is connected. The controller uses a modular plug system that plugs into the truck. I believe I have a blown fuse, but cannot find it in either the main truck fuse block or any of the trailer fuse blocks. the truck fuse block does have fuses for trailer lights. Can you advise me where the fuse is located? I have traced the wiring from the controller to the truck plug and find no inline fuse. Thank you for your help.

asked by: Mike A

Expert Reply:

If your 7-Way is not factory installed then you will need to make sure the blue and red wires under the hood at the power distribution box are connected. The red wire has a ring terminal and goes to the closest positive post in the power distribution box with a 30 amp fuse installed in the fuse location nearest the positive post, for power to the brake controller. The blue wire has a plug on it that you will need to remove.

You will need to run a length of Jacketed 2 Wire, 10 Gauge, # 10-2-1, wire from the 7-Way in the back of the truck to the junction box under the hood. Connect the white wire in the gray housing to the blue wire under the hood. Then, connect the black wire in the gray housing to the other auxiliary positive post in the power distribution box with a 40 amp fuse in the fuse location closest to the auxiliary positive post.

If your 7-Way is factory installed, the wire from the back 7-way to the front of the truck is already there you will just want to check under the hood to make sure the red and blue wires are connected and that the appropriate 30 amp and 40 amp fuses are installed.

After checking all of these things, if you are still having problems with the brakes not working then let me know and we can proceed from that point on to see what might still need to be checked.

I am sending a link to installing a brake controller on 1999-2006 Chevy/GMC trucks which will show you where the wires are attached and where the fuses would be located on your truck if your 7-Way was not factory installed.

expert reply by: Jeff D