Will The Roadmaster Diode Prevent Power From Solar Panels Back-Feeding To Tow Vehicle?

Question:

Good Morning- I have an fifth wheel with solar panels that charge the battery on the fifth wheel while we are going down the road. Because this voltage can be higher than the trucks output, it will flow back into the truck and cause the check trailer wiring message to come on and ultimately puts the brake controller into protection mode. I have disconnected the solar to prevent this from happening. Can this diode help and how would I wire it into the control box. If not is there another option? Thanks. Attached is a copy of the bulletin.

asked by: Ryan

Expert Reply:

The Single Diode # RM-690 is going to be a better option than the Diode # RM-790 as it only has the single input rather than a dual input. Ideally your 5th wheel should have come with a In-Vehicle BCDC Battery Charger # RED96FR which would prevent the power from backflowing either from the solar panels or when connected at a campground.

If you choose to go with the single diode you want to wire it in line of your 7-way charge line wiring before it enters the Junction Box # 3375601101. Do understand this part can fail so you will want to check it before towing to ensure it is working properly.

expert reply by: Bud M