How to Test Powered Module of Curt T-Connector Harness for 2018 Toyota Highlander

Question:

The connection use to work perfectly. The fuse in the Highlander fuse box is good and so is the fuse box of this connector. How can I check to see if the modulator is still working? In case it isn't remind me of the warranty. Thanks.

asked by: Gerd

Expert Reply:

In order to test the powered module of the Curt T-Connector Vehicle Wiring Harness # C56217 you will need to use a circuit tester such as the Cordless Circuit Tester # PTW2979 and test the wires going into the module, and then the wires coming out of the module. If there is power going into the module, but none coming out, that means it could be faulty and needs to be replaced. This harness does have a 1-year warranty. A converter will often go out due to a short in your trailer wiring, so it may not be the converter at all. You are going to want to make sure that no matter what you do check that wiring to ensure there are no broken, crimped, or otherwise damaged wires that are causing a short.

If it isn't the module check your grounds and be sure they are attached to clean, bare metal surfaces without any rust or paint; a poor ground is something that is the most common issue so I'd start there. If it does turn out to be the module and the connector is no longer under warranty I recommend going a different route and replacing it with the Tekonsha T-One Vehicle Wiring Harness # 118449 because the Tekonsha harnesses are far more reliable than the Curt harnesses.

I have also added a link to a help article on troubleshooting trailer wiring I recommend checking out.

expert reply by: Kyle S