Troubleshooting Trailer Wiring Harness Converter on 2008 Mercury Mariner

Question:

2008, Mercury, Mariner. My wiring on the trailer did not match on the vehecile kit that I purchased from you. So long story short I blew the fuse. I replaced the fuse and plugged a test light into the plug on the car and I have no power to either turning signal at the plug. It shows constant power, on the test light, for the trailer but no power to either trailer.

asked by: Bob

Expert Reply:

It sounds as if you might have shorted out your converter box. I will link you to a video that demonstrates how to test the converter. You will test the wires on the input and the output side of the converter. If you have signal entering, but not leaving the box, it will need to be replaced with the # 118551.

You should also check the fuse where the power wire connects at the battery. If that fuse is blown, replacing it might fix your problem.

If the fuse and/or converter was blown due to something being mis-wired, be sure to repair it before installing a new converter, or you will continue to blow up converters. If the converter blew due to a short in your trailer wiring, you will need to locate and repair the short before replacing the converter.

I will link you to our Wiring FAQ page that shows how the trailer should be wired.

expert reply by: Mike L