RVing Drives Me Nuts ---- Electrical Issue

Hoppypoppy wrote:
Brought my 2002 Cardinal home from storage last Fri. Checked lights - everything fine. 5er sat in front of my home til this morning. (Tues) Hooked it up, ready to go, no tail, brake or turn signal lights on right side only. Left side fine. First thought was a ground issue. Now the dumb question.....is the only ground on these rigs the ground included in the power plug to tow vehicle? Any other suggestions? Thanks all.

The 7 pin does not have a "right side" pin and a "left side" pin. Neither does it have a "right side" ground or a "left side" ground. If the problem was in the 7 pin, it would not just affect one side.

While the brake light and turn signal are one circuit, the tail light is a separate circuit/filament. If it was a hot wire, only the tail light, or, only the brake light/turn signal would not be working. It is unlikely that both the hot wires would fail at exactly the same time. (Unless a critter got in there and chewed them.)

The evidence (2 separate circuits, with one of them only affected on one side) points to a bad ground on the light fixture. Try running a temporary separate ground wire from the light fixture to a known good ground. I'll bet that solves the problem. If so, you can attach a permanent ground wire from the light fixture to ground.

If the ground between the 5er and the tow vehicle was the problem, it would not be only that one light fixture.