How to Prevent Stoplight Override of Turn Signals on Flat Towed Vehicle

Question:

My motorhome has combined brake/signals and the Crosstrek has three bulbs tail, a brake and a separate signal. The RM-154 will wire the tail lights and use the brake light as brake and signal. What my question is: when my Blue Ox brake pushes the brake pedal when the rv is braking it seems to me the brake/signal bulbs will be double fed 12 volts for my Crosstrek’s brake lights work regardless of the ignition key turned on or off. And therefore canceling a turn signal from being able to flash. Do I need to pull the brake light fuse or purchase a switch to turn the towed vehicle’s brake lights off so not to interfere with the motorhome’s power to the bulbs. I haven’t started any installations yet.

asked by: Dean

Expert Reply:

We have the Roadmaster Brake Light Relay part # RM-88400 which was designed for applications like yours and will prevent the supplemental braking system from overriding the turns signals of your tow bar wiring when the brake is applied.

expert reply by: Jameson C