Brake Lights On Jeep Do Not Work While In Tow Mode

Question:

I just bought a diesel motorhome with air brakes with the 7-pin plug I have a demco one play duro brake controller in my jeep. I am not getting the brake lights on the jeep to light when pressing brake pedal. Is the Electric brake pin on the 7-pin plug used in towing the jeep or is it strictly for towing trailers with electric brakes? signal lights work fine, just not the brake lites. I am wondering if the air brakes make a difference. I did not have air brakes on my previous gas motorhome. Theres a fuse location for electric brakes on the fuse box, and it does not have a fuse in it at the moment. would I hurt anything to put a fuse in it and try the brakes? thanks

asked by: Hb C

Expert Reply:

The issue you are having with your brake lights will have more to do with the flat-tow wiring harness rather than the supplemental braking system. That said, the stop light switch circuit does go dead on certain Jeeps while in tow mode so the incorporation of a Roadmaster Stop Light Switch Kit is needed. If you can give me the year and model of your Jeep I can then confirm if this is the case and if so, what the correct part number is.

Also, the SMI Stay-IN-Play DUO Supplemental Braking System part # SM99251 which I think is what you are referring to is for motorhomes with hydraulic brakes. It will not work with motorhomes that have air brakes so you will want to use the SMI Air Force One Supplemental Braking System part # SM99243 instead.

I am not sure what fuse you are talking about but if the brake lights work while not in tow mode then this would not be the cause of this.

expert reply by: Conner L