Trailer Left Side Running Lights are Dim

Question:

Im my trailerdouble axle, self wired the left side does not work correctly. I have cleaned and grinded my ground connections. I have checked my bulb and my connections. I have put a new light system on as well. My brake lights and blinkers work very well but you can hardly see my head/tale lights on the trailer. I need help asap.

asked by: Landon

Expert Reply:

If it is only the running light on the left side that is dim then the most likely issue is still a weak ground. You may need to run a jumper ground from that tail light assembly to another location. This is especially true if there is a license plate bracket between the tail light assembly and the trailer frame.

When you are testing the light are you doing so with the trailer coupled to the ball? If not, and you do try it with the trailer coupled to the ball and it starts working fine that is indicative of a ground issue and you will need to take another look at the ground locations for the trailer connector and the lights on the trailer.

Also check the vehicle and trailer side connectors. Make sure they are clean and free of corrosion inside, where the wires attach, and outside on the pins. I had a friend with a similar issue and the problem was a corroded running light pin on the vehicle side connector.

expert reply by: Michael H