Installation of Roadmaster Battery Charge Line Kit on 2025 Ford Maverick

Published 11/10/2025

Products Featured in This Question

Roadmaster Battery Charge Line Kit for Towed Vehicles

(1294)

$47.24

Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 7-Way to 6-Way Coiled Adapter Cord

(3350)

$186.26

Question:

RE: Demco RM 156-25 Charge line kit. I saw the video for installation on 2025 Ford Maverick. 2 main questions : Some installations indicate both a circuit breaker as well as a fuse be installed for redundancy. Is a 15 amp the right size for the circuit breaker and should it be a manual reset or automatic? No info in the instructions. What size amp fuse ? In the instruction diagram in Figure 1 it shows the charge line in the center as it should be , but in Figure 3 - it shows hooked up to 4. Should in not be at the center at 7 ? Thanks

asked by: Mark F

Expert Reply:

Hello again Mark; the Roadmaster Battery Charge Line Kit # RM-156-25 doesn't call for the installation of a fuse and Roadmaster doesn't find it necessary which is why you don't see it in the instructions. It comes with an automatic reset 15A circuit breaker so you don't need an extra one. You can add a 15A fuse if you really want to.

The reason you're seeing different positions on those diagrams is because they're two different connectors. Both are correct. One is the 6-way from your vehicle and the other is the 7-way on your motorhome. Flat tow wiring like the Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 7-Way to 6-Way Coiled Adapter Cord # RM-15267 includes the adapter cord which carries the functions over to the proper pins on the connectors.

expert reply by: Robin H

Roadmaster 6-Way Wiring Diagram
(click to enlarge)

Roadmaster 7-Way Wiring Diagram
(click to enlarge)

Mark F.

11/10/2025

The receptacle on the Maverick will have the charge line on the center post , correct ? Which means the receptacle on the motorhome for the charge line should also be in the center, otherwise it goes to the wrong component, say tailights ?? So you are saying that my umbilical cord does take the charge to the center post ? Thanks

Robin H.

11/10/2025

@MarkF any standard 7-way is going to have the 12V on pin 4 as indicated in the diagram. The adapter cord will match up the functions between the two different connectors. The charge line on pin 4 on the 7-way will run to the charge line on pin 2 on the 6-way connector on your vehicle. As long as you match the diagrams and use any standard 7-way RV to 6-way round cable you find on most flat towing setups everything will work as intended.