[sleepdog]

If all your other door locks are working it's most likely the wiring harness between the roof and rear hatch. There is a rubber boot that protects the harness between the roof and hatch but the wires inside become brittle over time and eventually crack. To repair mine I pulled the boot out of the roof side and cut it with a razor a few inches and rolled it up to expose the broken wires, stripped the insulation off the broken wires, and then used some crimp connectors on them. I had three broken wires altogether. Put the boot back and wrapped some electrical tape on it. Has worked fine ever since. Good luck!

 

[sleepdog]

When I was working on this problem I found that my mechanical hatch lock also worked very poorly, but it was due to lack of use more than anything. It was gunked up with dirt and dust from always using the electronic actuators. When the actuator stopped working I found the mechanical lock to be very problematic until it got regular use and then it was Ok.

Before he takes his rear hatch panels apart it's easier to check to boot since it's already exposed between the door and hatch. The actuator is likely still good if none of the other actuators have failed.