What Causes My Trailer Lights To Short Out

Updated 07/07/2017 | Published 07/05/2017

Products Featured in This Question

Dielectric Grease for Electrical Connectors, 2 oz.

(1494)

$10.94

Hook Probe Circuit Tester

(66)

$14.40

Question:

i dont have running lights or tail lights on my camper i got brake and turn signal s .When I jiggle the one bulb on the runnings lights i lost them. Dont know which fuse I look at all the ones that said trailer lights and change them still nothing ,look under hood and on the side of the dash .also change the 30 amp under the bed

asked by: Bill F

Expert Reply:

In order to determine the correct fuse associated with your camper's lighting system, I would need to know the year, make, and model of the vehicle in which you are using to tow the camper. If you can provide me with this information then I would be happy to tell which fuse to check. However, this sounds to me like you may have a wiring issue.

The first thing you will want to do is check all of the ground wires to ensure they are properly secured and not frayed or severed. The ground wires must be attached to a bare metal surface on your frame. The next thing you will need to do is look for corrosion in both the trailer and vehicle side connectors followed by corrosion in the bulb sockets. Clear all debris and material from the connectors and bulb sockets while using a bit of our Dielectric Grease for Electrical Connectors part # 11755 when re-connecting them.

If the problem still persists, you will need to begin looking for a short or frayed wire on the trailer's wiring harness. Trace each wire back to the lights to ensure there is no damaged or pinched wires. If no shorts are found, you will then need to start probing the wires directly behind the connector using a circuit tester like part # PTW2993. To do this you will need to have a friend sit in the vehicle and operate each of the trailer's lighting circuit while testing that corresponding wire for proper functionality to ensure the connector is functioning and to determine which wire is causing the problem.

I have attached a review video of the circuit tester for you that will further explain this process.

expert reply by: Conner L