Right Brake Light Does Not Work After Breakaway Switch Installation

Question:

Took my truck to a garage to have this brake charging system installed on my trailer. They hooked it up so it charges when my running lights are on. The auxiliary power on my 7 pin has constant power on my truck, and they were worried about it draining my truck battery. Now when I turn my lights on, my right rear brake light doesnt work. I think they messed up the installation and I need some help so I can fix it.

asked by: Anthony

Expert Reply:

That is odd that your right rear brake light does not work if they spliced the break away switch battery into your running light circuit. The brake lights and running lights typically run on two different circuits so it should not have been affected. I would recommend checking each of the connection points for possible cuts or frays to other wires nearby. It is possible that they may have accidentally cut or damaged a brake light wire creating a short that would cause your brake light to fail.

If you do not see any cuts or other damage at their connections points for the breakaway system, Then I would recommend starting the troubleshooting process from the beginning. First, use a circuit tester like # PTW2979 to see if there is a signal for the right rear brake light on the vehicle side trailer connector. If there is no signal, then the issue could be a blown fuse, poor ground or short on the vehicle wiring harness.

If you do have signal on the vehicle connector, then we know the issue is on the trailer. I would start at the trailer connector and look for any corrosion or debris on the pins that could be causing a disruption in signal and clean or repair accordingly. If the connector is in good condition, then make sure the ground wire from the connector is attached to a clean, bare metal surface on the frame.

After that, inspect the right turn/stop circuit on the trailer for any cuts, frays or damaged sections that could cause a short. Finally, inspect the light itself for a poor ground connection or a bad bulb if there are no signs of a short or damaged wire.

I have attached a wiring FAQ article that should help when troubleshooting the right brake light circuit.

I can also tell you that the charger from the Tekonsha Breakaway System, # 2028, is designed to wire into the 12v power circuit on a trailer and if there was a concern with the system draining a vehicle battery, it would have been designed differently. The battery is smaller than a standard vehicle battery and would not drain the vehicle battery when charging. I spoke with my contact at Tekonsha regarding the installation and he told me that installing the breakaway system in this manor should not harm the trailer or vehicle circuits in any way since the charger only draws 2 amps, but you may run into a dead battery if you do not tow frequently and leave the tail lights off when towing.