Trailer Connector Tests Okay But Will Not Operate Trailer Lights

Question:

When we check the power to the truck connector there is powere to all plugs but when we plug in the trailer no lights not matter what trailer we plug into.

asked by: Church

Expert Reply:

So what you are saying is that you are getting power for all functions at the trailer connector, but when you plug in a trailer, any trailer, the lights on the trailer do not work-is that correct?

Check your trailer connector on the vehicle, and make sure it is not damaged or overly corroded. If you can see green or white corrosion on the pins of the connector, it could prevent signal from reliably getting through to the trailer. Also, check the ground connection for the connector on the vehicle. The connector should be securely grounded to clean metal on the vehicle frame or chassis. If this connection is loose, it would explain why it tests okay with a tester grounded to the vehicle, but will not work when a trailer is plugged in.

expert reply by: Mike L