Troubleshooting Invisi Brake From Roadmaster Where Compressor Does Not Come On

Updated 04/01/2019 | Published 03/29/2019

Question:

Just had it installed today can not get the compressor to come on I had it taken out of a 2014 Gmc Terrain and put in our new 2019 Buick Envision

asked by: James D

Expert Reply:

In the installation instructions for the Roadmaster BrakeMaster # RM-8700 there are two fuses wired to the air compressor circuit. One 20 amp fuse on the power wire of the battery, and a 10 amp fuse connected on the blue wire that runs from the ignition switch to the air compressor.

Inspect these fuses and any poor or loose wiring connections. Try using a jumper wire 12-volt source to connect to the compressor to see if it operates. If the compressor works, then the issue is along the wiring. If the compressor does not work, then there may be an issue with the unit itself.

I have attached the wiring diagram to this page.

expert reply by: Jameson C