Troubleshooting Power to Both Running Lights and Left Turn Circuit After Converting 4-Way to 7-Way

Published 08/16/2018

Question:

Hello, I just installed the Hopkins 31345 trailer plug adapter kit in my 2017 Express and I have 12 Volts at both the Left Directional and the Running Lights when I turn on the Running Lights. I extended the 4 wires from the adapter to a 7 pin Hopkins trailer plug and now Im looking for a place to start. I did test at the plug, both the 7 and 4/5 pin. Power was not extended to the adapter until it was completely installed in an effort not to short any wiring... or at least I thought so... I do a lot of AC and DC wiring for over 50 years but I can make mistakes. Just looking for your experience.

asked by: James M

Expert Reply:

The Hopkins Plug-In Simple Vehicle Wiring Harness # 31345 that you installed is a confirmed fit for your 2017 Chevy Express Van so we can rule the harness out as the problem. It sounds like you extended the wiring from the 4-Way harness to a 7-Way like the Hopkins # HM48470 that features a 4- and 5-Way connector as well. I recommend making sure that the connections inside the 7-Way match the appropriate functions. It's also possible that there is a short between the running lights circuit and left turn/stop circuit that is causing the issue.

On the inside of the Hopkins 7-Way the running lights circuit will be at the 1 o'clock position and the left turn/stop circuit will be right next to it at the 3 o'clock position. Make sure you made the correct connections and look for any exposed wiring that might be coming into contact with each other. You may want to specifically check the frayed end of the wires that are going to each terminal to see if any stray strands might be wandering over to the neighboring circuit.

I have attached a diagram of the 7-Way connector that you might also find helpful.

expert reply by: Chris R