Troubleshooting Trailer Lights not Working with 2009 Honda Pilot

Updated 05/15/2020 | Published 05/13/2020

Question:

I installed the Optronics Led submersible trailer light kit on my boat trailer. I have a 4 to 7 pin adapter plugged into my 2009 Honda Pilot. I also have submersible led marker lights spliced in. But no joy I only get a dim drivers side turn signal on the trailer. No other lights work including break, passenger side nada, nothing. This Honda was equipped with a 7 way trailer connector. I use an adapter to join the 7 way to the 4 pin optronics supplied trailer harness. Im wondering if I need some kind of signal converter in the Honda? Have you had other folks with this problem?

asked by: David M

Expert Reply:

This is an issue we run in to quite commonly when installing Combination LED Trailer Tail Light part # STL9RB or any other trailer light. The good news it has nothing to do with the vehicle 99% of the time. The most common cause for this is bad grounding at your lights or at the wiring harness ground. When this came into the shop my first step would be to remove sand down to good steel and replace each ground. That will likely solve your issue.

The very dim light coming through is an indication that there is not enough ground to allow the voltage to run through properly. There is only enough ground available to allow that little bit of voltage through.

Please let me know if this does not solve your issue and we can go through the system together.

expert reply by: Randy B