Troubleshooting Trailer Brake Lights that Do Not Work When Bulbs and Voltage has Been Checked

Question:

Hi, I have a strange situation on my camper. My brake pole is working on my truck 7 pole connector. The brakes work on the trailer when I slide the switch on my controller. But the brake lights do not come on. I changed both bulbs but I get nothing. Just in case, I took a good, working and charged 12V battery and used that on the wiring receiver to power the brakes instead of my truck. Still nothing. Any ideas? Is there a breaker or something inside of the camper? It just seems strange since the electric brakes and lights should be on the same circuit I think. Thanks,

asked by: Marty

Expert Reply:

Check the grounds of the camper taillights. If the bulbs are good and you verified that they still don't work with 12 volts applied to the circuit then the only problem left is the grounds.

You can try running a jumper wire back from the assemblies to the main ground wire of your trailer wiring as well.

expert reply by: Jameson C