How To Hook Up Both the Tow Dolly and Vehicle Tail Lights To Motorhome

Updated 09/29/2024 | Published 09/18/2019

Products Featured in This Question

Roadmaster 4-Diode Universal Wiring Kit for Towed Vehicles - 4-Way Flat Connectors

(3357)

$88.90

Question:

i want to hook up both tow master dolly that has lights and use my tow vehicle lights...how do I do that

asked by: Jeff

Expert Reply:

In order to have both the tow dolly's and towed vehicle's lights active at the same time while being pulled behind a motorhome, the motorhome's trailer lighting circuits must be rated for the amp draw of both sets of lights. If that is the case then what you are going to need to do is make your own custom adapter as they don't offer anything for this purpose.

The parts you will need to make this adapter are the Epicord 7-Way Molded Trailer Plug with Junction Box part # 277-000141 and the Roadmaster Universal Hy-Power Diode Wiring Kit part # RM-154. The junction box will get installed near the tongue of the tow dolly. The trailer connector you have for the tow dolly will then be removed and ran directly to the junction box. Then in order to hook the towed vehicle's lights up to this junction box we first need to install the diodes and respective wires from the kit inside the vehicle. Once this is done we can then remove one of the trailer connectors on the extension loop and run that end of blunt cut wires to the junction box. The other end of the extension loop which is fixed to the tow dolly will be what you plug into the tow vehicle.

The above will then allow you to hook up both the tow dolly's and towed vehicle's lights up to the same trailer connector on the motorhome.

expert reply by: Conner L

Henry

9/27/2024

Can I put a 4 pin / 7 pin plug on back of motorhome plug the tow dolly into the 4 pin and use the 7 pin for the remote magnetic lights? Not sure about wiring a dual plug with the current my wiring and if theree is enough power for both

Jon G.

9/29/2024

@Henry You should be just fine by using the Adapter 4-Pole to 7-Pole and 4-Pole # 37185. The lights on your tow dolly as well as a Light Bar like the Part # LIW-LDTL-7B. We also have the Demco Light Kit # DM36MV which plugs into a 7-Way and then also has a 4-Way connector for your tow dolly to plug into so you don't have to add an adapter at all.