Troubleshooting Running Lights on 2010 Palomino Sabre 5th Wheel Trailer

Question:

I have a 2010 palomino sabre fifth wheel only my two side marker lights work. My back and top front running lights do not. What would be the problem.

asked by: Steve

Expert Reply:

There are several potential causes for the lighting malfunction on your trailer, ranging from bad bulbs in the specific fixtures to damaged wiring within the trailer frame to a weak ground wire connection.

You can do some simple tests to determine where the issue may be. If you have a spare 12V battery you can try applying power directly from the battery to the problem lights' contacts. If they work when powered directly then you know the issue is somewhere upstream within the trailer wiring.

If you have a circuit tester like # PTW2992 you can test for a signal on the wires where they enter the light fixture housings. If signals are there on the wires but the bulbs do not light, then the bulbs or fixtures are bad and need to be replaced. Please refer to the linked video for a demonstration of how to use the tester.

If there is any corrosion at all on the vehicle or trailer side connector contacts (even a slight greenish or whitish film can be a problem) then cleaning the contact surfaces may allow more current to pass through to power the lights. You can also apply the tester to the vehicle socket contacts to see if a 12V signal for the trailer lights is reaching it.

If you recently added or switched types of lights on the trailer, then it is possible that your wiring is not able to deliver enough power for all of them.

Please let me know the results of your testing so we can offer you additional recommendations.

expert reply by: Adam R