Troubleshooting Brake Controller Wiring of 2005 Chevy Suburban Not Working

Question:

truck has factory 7 pole plug at hitch.Brake , turn , back up work at plug. when plug in brake connector plug in box under dash, brake dosnt work. plug has no power?

asked by: TABITHA R

Expert Reply:

It's very common for GM vehicles made around the time as your 2005 Chevy Suburban to have brake controller issues related to the third brake light fuse of the vehicle. The third brake light fuse of the vehicle is very easy to blow and when it goes out it also prevents brake controllers from working too since that same circuit is tied to the stoplight circuit. You can easily check this by stepping on the brake and seeing if the third brake light of the vehicle comes on or not. The fuse is normally labelled CHMSL.

Other possibility is that the brake controller wiring is not completed under the hood of your vehicle which is also really common. All those connections are covered in the attached help article.

expert reply by: Jameson C