Convert Motorhomes 4 Way To 7 Way And Install Charge Line For Towed Vehicle Battery
Question:
I have 4 wires coming from motorhome
asked by: George L
Expert Reply:
If you do not have a 4 way flat and just have 4 wires at the back of your motorhome, then use Hopkins Endurance Quick-Fix Replacement 4-Way Flat Trailer Connector w LED Test Lights - Vehicle End # HM48190. This will connect your 4 wires to a 4 way flat plug. Once you have a 4 way flat, you can convert to 7 way with Buyers Products Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat # 337TC1474P.
Your 4 way flat will plug into the 4 way harness on this adapter, then you will need to ground the white wire to your motorhome. The adapter's black wire should be connected to the positive terminal on your motorhome's battery using 10 Gauge Primary Wire # 10-1-1. You will want to add 40 Amp In-Line Circuit Breaker # 9510 in the wire before connecting to the battery.
Now you can use Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 7-Wire to 6-Wire Straight Cord # RM-152-98146-7. This will connect to your motorhome's 7 way and be mounted on your towed vehicle's front bumper for light signal output and charge line output. This kit comes with everything to connect your RV lighting wires to the towed vehicle's lights. Use Roadmaster Battery Charge Line Kit for Towed Vehicles # RM-156-25 to keep your towed vehicle's battery charged/maintained. One end connects to the 12v wire on the bumper-mounted kit mentioned above, and the other end connects to the towed vehicle's battery.
In order to use a supplemental braking system, use 12 Volt Outlet Kit # RM-9332 which will connect to the towed vehicle's battery and be ran into the cab to power the supplemental braking system. I have attached demonstration videos for these products.
![Andrew N](https://images.etrailer.com/static/images/catg/people/2347_tn.jpg)
Products Referenced in This Question
Buyers Products Trailer Connector Adapter - 4-Way to 7-Way RV and 4-Way Flat
- Trailer Wiring
- Wiring Adapters
- Multi-Function Adapter
- 0 - 5 Feet Long
- 4 Flat
- Plug and Lead
- Buyers Products
more information >
40 Amp In-Line Circuit Breaker - Perpendicular Mount Bracket
- Accessories and Parts
- Wiring
- Circuit Breaker
- 40 Amp
- Pollak
more information >
Hopkins Endurance Quick-Fix Replacement 4-Way Flat Trailer Connector w LED Test Lights - Vehicle End
- Trailer Wiring
- Trailer Connectors
- Vehicle End Connector
- Plug Only
- 4 Flat
- Hopkins
more information >
Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 7-Wire to 6-Wire Straight Cord
- Tow Bar Wiring
- Splices into Vehicle Wiring
- Diode Kit
- Universal
- Tail Light Mount
- Roadmaster
more information >
Roadmaster Battery Charge Line Kit for Towed Vehicles
- Accessories and Parts
- Tow Bar Wiring
- Battery Charge Line Kit
- Roadmaster
more information >
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