Troubleshooting Curt Trailer Wiring Harness and Adapter Installation

Question:

I put on the Curt wiring harness and the 4 to 7 and 4 adapter on my 2006 Toyota Rav 4. The power lit and rt,tm,lt lites are all staying on all the time. I have the hot wire to the battery with 40amp inline breaker. Is this wrong?. Thought just 12v lite was suppose to stay on. Thanks.

asked by: Jimmy P

Helpful Expert Reply:

Thank you for your recent purchase of a Curt trailer wiring harness # C56165 and 4 Pole to 7 Pole and 4 Pole Adapter # C57674.

LEDs take very little power to illuminate. Some wiring harnesses can pass a tiny amount of power at all times - even when the light functions are NOT actually activated on the vehicle - that can cause sensitive LEDs to light up. You are right that normally only the 12V circuit's LED should be lit.

You can find out for sure by disconnecting the adapter and applying a tester like # PTW2993 directly to the pins on the 4-pole harness. This will tell you if the harness itself is generating the correct signals and whether the adapter LEDs lighting up is a result of just their sensitivity or a harness malfunction. The linked video illustrates use of the tester.

Please note that the Curt wiring harness # C56165 is to be installed to your battery through the included fuse and fuse holder, NOT through a 40-amp circuit breaker.

expert reply by: Adam R