Full 12 Volts Not Reaching Roadmaster Battery Charge Line Kit for Towed Vehicle

Updated 08/21/2019 | Published 08/20/2019

Question:

Hi I bought the above kit as well as the blue ox 7 to 6 wire from e trailer for my MotorHome to 2017 Toyota. When plugged in all lights work as they should and there is 12/13 v at the female connection in the motor home. As the roadmaster instructions say I tested the connection by ground and at the disconnected red wire. It only shows 4/5 volts. I tested the wire on the other side of the circuit breaker and it shows 4/5 volts I am hoping you can tell me something I have done wrong. Thanks. You have always been so helpful

asked by: Bill F

Helpful Expert Reply:

I am not sure if you have already tested the battery charge line circuit on the motorhome's 7-way but if not this will be your next step. If you don't get 12 volts here then there is an issue with this circuit on your motorhome. Aside from tracing the wire back I don't have much to resolve this issue so easiest option would be to just run your own wire with the Roadmaster Battery Charge Line Kit for Motorhomes part # RM-156-75. If you do get 12 volts on the battery charge line circuit on the motorhome's 7-way then you need to start checking the wire that leads from this to the vehicle's battery.

I am not exactly sure where you are testing the wires at so if you can provide more info on this I may have additional advice for you as well.

expert reply by: Conner L