Brake Lamps of Travel Trailer Towed by 2000 GMC Sierra Not Functioning

Question:

Trailer brake lights dont work. All other lights work good including turn signals. It seems truck is not sending brake signal. What can I check? It uses a 7 pin connector.

asked by: Dennis

Expert Reply:

Are the brake lamps on your truck working correctly? If not, check the fuse box under the hood. Make sure the CHMSL and the Brake Stop Lamp fuses are not blown (see legend on inside of fuse box lid) and replace if necessary.

Does your truck have the OEM 7-way? If not, a taillight converter like # C59496 needs to be used. The inputs would tap into the wiring harnesses feeding the taillight assemblies, and the outputs can wire directly into the 7-way as shown in the trailer wiring FAQ I have linked you to.

If the 7-way is factory installed and all the brake lamps work okay, the simplest and least expensive fix would be to simply bypass the lighting portion of the factory tow package by installing the # C59496 mentioned above.

expert reply by: Mike L