Hi all,
I have a 2016 L4H3 Transit van that will not lock the rear door for me but has no "door ajar" message on the dash (so it is closing). I have tried a number of different things so I will try explain the problem as I understand it!
I first checked the latch was closing correctly and making contact with the striker bolt and all that was working fine with no plastic pieces impeding the closing of the latch.
I checked this forum and seen the rear door harness often breaks at the door hinge point, I pulled the harness through the boot and found no suspect wires. Not yet satisfied I hadn't missed something I done a continuity check on the harness and it all passed so I can now rule out the harness.
Next I bought a replacement door latch as I couldn't hear the door even trying to lock so thought it could be the actuator. The replacement lock didn't solve my problem.
Before doing anything else I thought at this stage to check the fuses for the central locking. Fuse number 1 (Central locking system 2) on the BCM had burnt out, slowly by the looks of it. I replaced it and had no difference in operation.
Next I tried to check the inputs to the rear door harness to try figure out what all of them do but got nowhere with it really. After locking and unlocking many times fuse number 2 (Central locking system 1) burnt out on me, again looked like a slow break. After replacing that too, the rear door still doesn't lock and I'm scratching my head. The main harness has been covered away as the van is converted into a camper van so it's hard to check that wiring for any frays although I know there's no screws going in near it or any sharp edges.
My next option is to send it to the garage but I thought I'd reach out with you before I spend a lot of money at a garage.
Can anyone provide a schematic of rear door lock? I can't find one online and if I could find out which wire(s) are at fault it would be a big help!