Troubleshooting Overloaded Vehicle Harness On a 2015 Ford Transit T250

Question:

I have a 2015 Ford Transit T250, without tow package. I installed a Curt C56249 back in 2017 and towed plenty with it with no problems. Recently I needed to tow a trailer with a 7 pin connection, so I ordered a Curt C57672. I plugged the C56249 into it, and I was not getting anything. I figured the box mustve shorted, so I cut the black box out of the C56249 assembly and direct wired in the C57672. I used a Tow Doctor to confirm that everything was working. Then, when I picked up the trailer and plugged it in, nothing worked on the trailer and the van displayed blinker and brake fault codes, and the driver rear light assembly quit working. Now with or without anything plugged in, I have no driver side rear lights. It seems to me that the C56249 assembly must have been faulty, and when I direct wired in the C57672 assembly, it was too much of a draw and the BCM in the van shut off the circuit. My plan is to purchase a Curt C56327 to replace the old C56249, plug it into the existing C57672, then use FORscan to reset the BCM for a tow module. Does that sound right to you? Thanks in advance.

asked by: Jeremiah H

Expert Reply:

That sounds correct to me. When you cut off the Curt T-Connector Vehicle Wiring Harness # C56327 converter box, it tried to pull all the power for the trailer circuits off the vehicle harness on your 2015 Ford Transit T250. It hopefully only damaged the fuses and not parts of the vehicle harness. Be sure to check the power wire that ran to the converter and see if the fuse was damaged or any of the harness is damaged as that would explain why it was not working when you recently tried to use it. Mice tend to be very attracted to this wire as it is ran directly from the battery under the vehicle and always has power.

The Curt T-Connector Vehicle Wiring Harness # C56327 should get your 4-way flat harness portion of the circuit working again. But be sure to check the fuses on your Transit and replace any wiring that is damaged.

expert reply by: Bud M