What Would Cause Trailer Wiring to Prevent Vehicle Taillights from Functioning

Question:

Hello I bought and installed the TeKonsha 118727 T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector on my 2019 Jeep Grand Cherokee Altitude. All worked fine for awhile. But now my drivers side taillight brake or blinker does not work. I disconnect from harness and connect normal no harness just factory setup and all works fine. Is this a bad controller unit?

asked by: Mike S

Expert Reply:

Typically when this happens it's that one of the pins of the connectors unseated and stopped allowing the circuits to pass back through to the vehicle wiring and allow the taillights to function. Since the converter box does not integrate at all into this it's not usually the trailer wiring harness. I'd try plugging the harness back in to see if that takes care of the issue.

expert reply by: Jameson C