Troubleshooting Curt 55510 Trailer Wiring Harness with Low Voltage

Updated 09/17/2018 | Published 09/15/2018

Question:

Installed. Only getting about 7.7 volts out of harness. Ground wire is grounded to chassis. All functions work on the plug 7 volt. When plugged into the boat trailer there is not enough power to run the tail lights and marker lights. Turn signals work, brakes work. Checked continuity between ground and other grounds, solid connection. The converter has always only put out low voltage. Is the converter box faulty? Only a couple of months old.

asked by: Mark G

Expert Reply:

Your problem could be the converter box. Test the wires on the harness before the box and see if you get the same voltage. If you do then the box isn't the issue and it's somewhere in the wiring before that. In this case you'll need to keep tracing the wires towards the front of the truck to find the problem. If the voltage on the # C55510 harness before the converter box is normal and still low at the connector then the converter is bad.

expert reply by: Charles S