Troubleshooting Trailer Power Connection on 2006 Peterbilt 387 Tractor Trailer

Updated 04/12/2018 | Published 04/11/2018

Question:

Please, can you tell me where is the fuse for the trailer located in a 2006 peterbilt 387? I connect the cables from the truck to the trailer , and It doesnt work. I checked with a electricity tester and it shows that the connect on the truck only have electricity in one of the pins. So I dont know if the problem is the connector or the fuser wich I dont know yhe location.

asked by: Eric R

Helpful Expert Reply:

I don't have the ability to find the fuse locations on your truck. I searched the owners manual and didn't have anything that referenced the trailer fuses other than the trailer load center location being on the inside left-hand frame rail near the air tank. It is stated to contain standard fuses and relays controlling the trailer power, trailer abs power, and trailer lighting protection.

It sounds like you are missing all but one function of your trailer connector. I recommend using a circuit tester like # PTW2993 to test each wire location once you have confirmed the fuses and/or relays are good. It sounds like too many wires not working to be a short, so I recommend you first test your ground connection because that could cause many issues like this if it is not connected to a bare metal surface free of corrosion and debris.

expert reply by: Jason S