Troubleshooting A Non-Working Light Function With Diode Wiring

Updated 05/03/2023 | Published 05/01/2023

Question:

I installed this kit a year and a half back. Everything worked fine, but now the right turn signal quit. Getting power to coach plug with signal light on. Have continuity plug to plug. Have continuity from toad plug to diode and from light plug to end of wire. Can this be the diode has gone bad? Thanks!

asked by: MARK H

Expert Reply:

Since the diodes in the Demco 4-Diode Universal Towed Vehicle Wiring Kit w/ 7-Wire to 6-Wire Coiled Connector # DM9523010-54 use spade terminal connectors the easiest way to test the diode would be to swap the connections on the diode in question and test your light functions to see if the terminal on the diode is the issue.

If it randomly stopped working then the cause is typically just a loose connection or a bad ground so I would check the connections and make sure there's no damage to the wires.

expert reply by: Kevin C