Troubleshooting Running Lights that are Blinking When Turned On

Question:

I have recently put my truck bed/bumper back on and re-attached the wires to the original 7-way plug on the bumper. I plugged in my camper and the running lights and blinkers work until I turn on the running lamps. When I do this all the lights flash on the camper. Now, I have read a few pages on this website and have isolated the problem to my truck via plugging in my other truck to the camper with no problems and by using my circuit tester. I have unplugged the stock 7 way connector to isolate it from the truck itself and have found that if I put my circuit tester on the brown running lamps wire and the ground of it to the dark green wire then my tester light will blink. What will fix this?

asked by: Cody

Expert Reply:

Whenever we see lighting issues it usually stems from a bad ground or a short somewhere. This can be the result of a bad 7-Way connector or wiring. Since you have exposed wires where you have done your splicing I highly recommend using some heat shrink butt connectors to get your wiring all sealed up properly.

You can use part # DW05745-5 for the bigger 12-10 gauge wires and part # DW05744-5 for the smaller 16-14 gauge wires. These are heat shrink connectors which will seal around the wires when heat is applied for a watertight fit.

Next you need to check all of your grounds to make sure they are securely connected to a clean, bare-metal surface. Even some paint or dirt can cause an issue.

If your grounds look good then you need to take a close look at the wiring for your running lights. Look for places where it is corroded, bent, exposed, or damaged and replace as necessary.

Let me know if you are still having problems and I can help you troubleshoot further.

expert reply by: Jon G