Troubleshooting Trailer Brake Controller Won't Turn On When Wired to GMC Sierra

Updated 04/08/2019 | Published 04/05/2019

Question:

Hi I installed the wiring harness that came with my 2016 GMC Sierra for the trailer brakes. I wired it to a Draw-Tite electronic brake controller. Model number is 20191. It won’t turn on at all. It seems to be wired correctly. Is there anything else I need to do or is in possibly not compatible??

asked by: Russell S

Expert Reply:

The Draw-Tite I-Stop IQ model 20191 Brake Controller is an older model but it should be compatible with the factory harness on your 2016 GMC Sierra.

If the unit isn't powering on at all when wired to the truck then there might be a blown or missing fuse under the hood. I took a look at the online owner's manual for your Sierra and it states that the fuse for the factory brake controller harness should be located at the number 1 position inside the engine compartment fuse block located on the driver side of the truck.

Check to make sure this fuse is present and in good condition, replacing as needed.

If this does not resolve the issue please let me know and we can continue to troubleshoot.

expert reply by: Chris R