Troubleshooting a Trailer with no Lights Functioning Towed by 2005 Dodge Ram 1500 4-Way

Question:

2005 Dodge Ram 1500 has a 4 hole/ 4 wire connection and the light kit on my utility trailer has 5 wire and 4 holes. think I wired it right but nothing works. thanks

asked by: Stanley B

Expert Reply:

The first thing we need to do is determine if the problem is on the truck or the trailer. The easiest way to determine this is to get a circuit tester like our part # PTW2993 and test the circuits individually as you apply the different tail light functions. Check out the video I attached to see how this is done.

If the problem appears to be on the truck you will need to check the wiring of the connector looking for shorts or corrosion. Look for corrosion in the connector especially since that is usually the culprit with problems like this.

If the problem is on the trailer you would want to first make sure you all the wires are attached to a clean metal surface first and then check all the wires for cuts or anything else that could cause the circuits to short out. Corrosion in the trailer connector should also be checked for and cleaned.

The reason your trailer wiring has 5 wires with 4 connection points is because your tail light circuit runs to both the left and right side of the trailer yet it is only one circuit on the connector. This is called wishbone wiring.

I attached an FAQ on wiring that you might find informative also.

expert reply by: Jameson C