Primus Brake Controller Sets Off Warning Lamps on 2010 Toyota Highlander w/Manual Override is Used

Question:

I just installed the subject brake controller on my 2010 Toyota Highlander non hybrid. This was a replacement for a Tekonsha Voyager unit. I have not hitched up my trailer yet, but without the towing harness plugged in, if I move the manual tab on the controller with my ignition on, it sets off a brake and antiskid warning lamp on my vehicles instrument cluster. I have to turn the car off and back on to reset these warning lamps. I also noted when checking voltage at the brake light switch during installation of this unit, that the switch only puts out about 2 volts. Otherwise, the Primus LED seems to be providing the proper indications for no trailer hooked up yet. The Voyager unit worked fine. I do not believe the Highlanders warning lamps should be activated like this, and assume it has something to do with the Primus function to activate trailer brake lights when the manual slider is used. Will this problem go away once I hook up a trailer and its towing harness? Thanks.

asked by: Colby S

Expert Reply:

It sounds like you do not have the red brake controller wire attached to the correct wire on the brake switch. There is more than one wire that will have power with the brake pedal pressed. You need the one that only has power with the pedal pressed and no power at any other time such as with the headlights on or the turn signals engaged. On a 2010 Toyota Highlander the correct wire should be the light blue wire on the brake switch.

The Voyager brake controller you used to have also is supposed to light the vehicle brake lights when the manual override is used. Most every brake controller does that now because it is required by law in California.

expert reply by: Michael H