Troubleshooting Motorhome 4-Way that Only has Turn Signals and Not Brake Lights

Question:

My motorhome has a separate amber rear turn signal with a 1156 bulb. The tail light, break light, and emergency flashers all work on another bulb. All rear lights work fine on the motorhome. When I connect the flat 4 wire tow lights, magnetic type, non LED, everything works, except the brake light on the tow lights. I can connect the same tow lights to my car and they work fine. Is it because of the separate turn signal light bulb on the motorhome? If so what is a fix? Thanks

asked by: Dennis B

Expert Reply:

If you have a 4-way trailer wiring harness on your motorhome most likely it has already had the turn signal light circuits converted so that the 4-way would function properly. What you can do is test the 4-way with a circuit tester like part # PTW2993to verify this. I attached a video that shows how to do this.

It is possible that someone wired up a 4-way to your motorhome incorrectly though. If so, then you would need to use a converter harness like part # HM48895 to properly wire your motorhome with a 4-way.

expert reply by: Jameson C