Dash Lights Flash When Trailer Is Plugged In To Connector On Truck

Updated 11/02/2015 | Published 10/30/2015

Question:

I have a 93 cummins when I hook up a double axle trailer and plug in the seven way all my dash lights flash. Any ideas?

asked by: Kyle W

Expert Reply:

It sounds like there is a short in the system. You didn't say if this is a new 7-way on your truck or trailer and if it is not, was it working before this problem?

The first thing I recommend is to disconnect the trailer and use a circuit tester like part # PTW2993 to check the trailer connector on the truck. Check each function to make sure they are all working properly. If everything checks out okay, you will need to move to the trailer.

Check the trailer wiring for loose or damaged wires, especially the ground wire connections. Check the connectors for any signs of dirt or corrosion and fix any of the problems found. If all of the wiring checks out on the trailer you will need a 12V power source and check the trailer wiring harness to make sure it is wired so that it matches the connector on the truck.

I have attached a helpful article you can check out.

expert reply by: Jeffrey L