Troubleshooting Running Lights and 12V Power Not Working on 2001 Chevrolet Suburban 7-Way  

Question:

Helpful Expert Reply:

In order to troubleshoot the running lights and 12V power not working properly I would start by checking the 7-way connection on your vehicle. Make sure there is no corrosion or damage present. Even if you do not see any corrosion, it wouldn't hurt to go ahead and clean it. Since this is a new trailer, I will assume the trailer side 7-way does not have an issue.

Once you have checked your 7-way, go ahead and check your ground connection. Make sure it is secure on a clean, bare-metal surface. Poor ground connections are often the cause of a lot of different issues.

As far as the running lights go, it is also possible that you have an overload situation if the trailer lights are overloading your wiring harness. In that case you would need to know the maximum amperage rating of the wiring harness as well as the draw of the trailer lights. This would not, however, impact the 12V so you would still have a different issue. If you are still experiencing the same problems it is time to do some testing.

You will want a circuit tester like the # PTW2993. Start by testing the 12V power and running lights on your 7-way connection. If these check out then the issue is with your trailer and I would recommend asking the place you bought it from to take a look at it since it is a new trailer. If you find that these are not working at the rear of your vehicle, trace the wires forward and continue to test as you go. More than likely you have a short somewhere, so keep an eye out for any exposed copper wiring and repair as necessary.

I have attached some helpful articles on wiring for your reference. The article on troubleshooting 4-way and 5-way wiring lists amperage draws for common trailer lights at the bottom under method 5 should you wish to check to see if you are overloading the wiring harness. If you are still unable to get your running lights and 12V power to work, feel free to reach out and I will help you troubleshoot further.

expert reply by: Robin H

1