Troubleshooting Trailer Lights Not Working With 2005 Jeep Grand Cherokee

Published 08/06/2015

Question:

I have the same problem as below for a diffrent car. Can you tell me what trailer connector,relays and video I need for a 2005 jeep Grand cherokee Larado 3.7? Thank You Question: I have no running lights or brake lights on my boat trailer. But when I use my key fob to lock the doors on my truck the trailer lights blink just like my tail lights on my truck. Does that sound like bad relays. asked by Expert Reply: It is very possible that a relay for the running light tow package wiring is not functioning or is missing. What can happen sometimes is if the relay is not there, only some power can get sent back to the trailer but a full load will not work. This could be why the lights blink when you lock the truck with the key fob but do not work when constant power is applied. The 2004 and 2005 Nissan Titan trucks only require two relays. The relays in questions are included with the Hopkins trailer connector, # N40975. The relays are # C57000. I have included a link to a video showing a typical installation for you.

asked by: Jim B

Expert Reply:

You said you have the same problem as a customer had with a Nissan Titan. If you have a wiring harness installed and are having these issues, it sounds like you have a blown fuse or bad relay on your Jeep. I did some research and found that there are 2 relays for your vehicle for trailer towing. They are in position 5 and 6. These would be items you need to get from your dealer if they are missing or bad. The fuse box is located under the left side of the dash behind a panel.

The fuses I found for towing are in position 9, 19, and 21. You will need to check these as well and make sure they are not blown and need to be replaced.

The wiring harnesses we offer for your Jeep do not have relays included as the kit for the Nissan.

expert reply by: Jeffrey L