Curt Trailer Wiring Harness on 2010 Toyota RAV4 Shows Power Even with Vehicle Off

Question:

I installed the C56165 wiring harness in a Toyota 2010 RAV4. With all lights turn OFF, I checked the connector outputs with a volt meter and get 12.1 volts on the brown, green, and yellow wire contacts. Still with all lights turned off, when I check those contacts with a 12 Volt light bulb the bulb doesnt light. When I turn the lights on, turn signal on, brakes on and check the contacts again with a light bulb everything works normally. Why is there voltage on the contacts when the lights are turned off?

asked by: Cliff C

Expert Reply:

What you are describing seems to be common in some Curt trailer wiring harnesses that use a powered converter such as # C56165. If you were to pull the fuse out of the fuse holder it should not have power any more (with the vehicle on or off). If that happens then that is exactly the issue. It would only be a problem if you left the trailer connected or anything that would draw power.

If it happens even with the fuse pulled then there is some sort of wiring issue on the vehicle, a short circuit, and you would need to have that inspected by a mechanic or the dealer. But to me it sounds like the Curt powered converter issue.

expert reply by: Michael H