Why Ground Wire Is Required On Towed Vehicle When Installing Tow Bar Wiring

Updated 06/15/2016 | Published 06/14/2016

Question:

The ground to the lights have nothing to do with grounding to the towed vehicle body. Why are you installing a ground wire to the body on the passenger side of the towed vehicle. Grounding comes from the towing vehicle.

asked by: Woody

Expert Reply:

As with the installation of lights on a trailer, the lights must be grounded, either through the mounting hardware which is the case for many lights. As with trailer wiring the # RM-155 needs the bulbs to be grounded to the vehicle to complete the circuit.

It is true you get the ground from the towing vehicle but the in order for the circuit to be complete the towed vehicle wiring has to be grounded to the towed vehicle as well. I have attached a drawing from the installation instructions that show how the wiring is to be run you can check out.

expert reply by: Jeffrey L