Troubleshooting Trailer Lights and Blower Motor for 2015 Jeep Cherokee After Launching Boat

Question:

Hello, I recently had a trailer hitch and wiring installed on my 2015 Jeep Cherokee Trailhawk. The wiring is a 4-way flat. I used an adapter in order to pull my recently purchased boat. 4-way flat to 7-way round. For the first day or so i had no problems pulling the trailer and the lights were all working properly. Unfortunately, the first day I launched the boat in water, i realized the trailer lights are now not working and additionally, my blower motor for AC/Heat is also not working. I checked almost every single fuse but they all appear fine. I have not checked the relays. Was wondering if you are familiar with a similar situation or if there is a specific fuse / relay I should spend specific time checking. Thanks in advance!

asked by: John

Expert Reply:

My first thought after reading this is if you disconnected the wiring from your trailer before you backed your trailer in the water to launch your boat. If you didn't then that would explain the issue. Since water and electricity don't like each other very much what probably happened is that (if you didn't disconnect anything) you had a short somewhere and you need to inspect all of your wiring. It could be that the wiring connector itself either on your 2015 Jeep Cherokee or your boat trailer has been shot.

Check your connectors for any corrosion as well as the wiring on your trailer for any places that have corrosion or are bent and replace as necessary. Using dielectric grease like part # 11755 helps to protect the connectors from debris, corrosion, and water.

I'm not sure why your AC/Heat is not working but it definitely could be related. Try checking the fuse in the 39 position as that should be your HVAC motor. If you installed the 4-Way on your Cherokee aftermarket then it could be that the module that came with it is toast as well, especially if your Jeep lights are working. You can verify this by using a circuit tester # PTW2979 or a multimeter # PTW1714 to test the functions of the 4-Way and ensure they are working properly (see attached photo).

expert reply by: Jon G