trailer brake control wiring

Printed From: the12volt.com
Forum Name: Lights, Neon, LEDs, HIDs
Forum Discription: Under Car Lighting, Strobe Lights, Fog Lights, Headlights, HIDs, DRL, Tail Lights, Brake Lights, Dashboard Lights, WigWag, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=112209
Printed Date: May 03, 2025 at 8:45 PM

Topic: trailer brake control wiring

Posted By: kranny
Subject: trailer brake control wiring
Date Posted: March 08, 2009 at 5:00 PM

I have an 08 chevy trailblazer. I just installed a trailer brake control. All trailer lights work fine.Trailer brakes will work only if I press the manual brake lever on the controller and the light on controller will come on. No light and no brakes when I push on the cars brake pedal. Is there a fuse or wire that needs to be connected somewhere? I only connected the orange (+) to red. the dark blue (aux) to brakes, and the black (-) to gnd. I did not use the light blue wire (chmsl). I also connected the chassis wiringring terminal to the emty stud on the underhood electrical center. There is 12 volts at the plug.

Replies:

Posted By: Ween
Date Posted: March 08, 2009 at 9:01 PM

hi,

the 'chmsl' lead is the input to the controller. if that isn't connected, the controller will operate as you described. under the drivers dash, along the harness on the left side, there are four leads GM provides to wire up an electric brake controller. the thin light blue there should be the input to the controller. all wires are labelled if i remember correctly.

Posted By: kranny
Date Posted: March 09, 2009 at 9:52 AM

Hey ween, thanks for the info. I did as you said .I now have brakes when I push break pedal! I used this brake control on 2 dodge products and on a nissan titan and only had to use the tree wires on them thus the confusion on my part. hope this will help others also.

Thanks again.

Kranny