Why are my towing lights not working?
Many trailer problems are due to a poor grounding connection, which is usually the white wire coming out of the trailer plug. If the ground is poor, lights may work intermittently or not at all. Even if the wiring to the plug is adequate, make sure that the ground connections to the trailer frame are good.
Why is my left trailer light not working?
Poor ground connections are the most common culprit of trailer wiring issues. The lights will have either a ground wire or they will ground through the mounting hardware. If you do not have any signal on the left stop/turn or running light circuit, then the issue could be in the connector itself.
What happens when your trailer lights are not working?
When your trailer lights aren’t working, your trailer is not working, and you are losing valuable time and money.
What are the running lights on a trailer?
The next thing is to make sure the wires on the trailer plug is wired properly to the trailer. If you have a 4-Way connector on the trailer the white wire is for ground, the green wire for right turn and brake, yellow wire for left turn and brake, and the brown wire is for running lights. I am including a link to a FAQ page on trailer wiring.
What to do if your trailer turn signal is not correct?
If you still have the problem, disconnect the trailer to test the 4-Way on the vehicle using a circuit tester like # 40376. First, test the wiring going into the convert box on # 118426 from the vehicle tail light wiring. If the signals are not correct then you have a problem with the vehicle wiring.
Can a 12V battery be used for a trailer light?
A power drill will be used to install the screws for the ground wires. A 12V battery can also be useful for testing trailer lights in situations where you don’t have access to the vehicle or you suspect an issue with a particular trailer light. Trailer lights work except for one function: brake, right turn, left turn, or tail.