Troubleshooting Low Voltage To Trailer Connector On a 2007 Honda Ridgeline

Updated 07/10/2021 | Published 07/08/2021

Question:

Parking/running lights work on boat trailer but nothing else. Used jumper battery pack on trailer and everything works as it should. Tested tow vehicle: - Getting 11.93V on parking light pin. - When testing turn signal pin getting 7 to 11.5V while flashing. - brake light pins 10.9V with parking lights on. Any idea why Im not getting a full 12 to 14V on all pins when testing? Thanks for any help.

asked by: Bob W

Expert Reply:

The first place that I recommend starting is the battery inside your 2007 Honda Ridgeline. You will need to test the battery voltage with a Multimeter # PT89ZR. Be sure to test the battery in the same condition that you tested the lighting circuits on the trailer connector. Depending on the age and condition of the battery it will typically drop voltage as power is pulled from it. The wiring can also cause a voltage drop depending on the condition of the wiring.

Repeat all the tests that you preformed at the lighting connection and record the voltage levels at the battery. If you see more than a 1 volt difference between the battery volt levels and the voltage on the trailer connector you may have some damaged wiring that is shorting out in the harness. You can follow the harness looking for any signs of physical damage. If it is an OEM harness you may need to take it to a service center for proper testing of the harness.

If you get the same to almost same voltage it sounds like your battery is either low on charge or will not hold a charge properly with voltage that low. You should have the battery tested and possibly replaced if bad. Be sure that your charging system is also good if you have the engine running while performing these tests.

expert reply by: Bud M