Troubleshooting 7-Way to 5-Way Adapter that Doesn't Activate Reverse Lock Out Solenoid

Question:

I have a seven round to five flat trailer harness connector and when it is plugged into my truck the ground like indicator is on whether a trailer is connected to it or not. Does this mean I have a grounding issue on my truck? My experience has been that I have a trailer that has all the lights working, except for the running lights. I have another trailer that all lights work, except for the surge brakes do not lock out when in reverse, but do work when another vehicle is attached to it.

asked by: Reid R

Expert Reply:

What ground light indicator is on? Do you have a circuit tester built into the adapter or something else? The surge brakes not locking out is most likely that your 7-way does not have the reverse light circuit active as it's not always. You'll need to run the center pin of the 7-way to the reverse light circuit by tapping into the power wire for the reverse lights on the vehicle.

expert reply by: Jameson C