Backhatch wont open from outside

Here's a PDF of the hatch assembly

 

This is an interesting problem......IF all the reported details are correct.

The fact that it opens at all should mean that the actuator is working.
The fact that it unlocks the other doors should mean that the switch contact for the handle is working too.

Or is this latch a combination of a direct mechanical operation from the nearby handles AND electrical actuation from a remote switch ??

 

the emergency handle on the inside is probably mechanical.

 

My guess is that the door lock motor is going to be in the hatch floor. Where are you looking?

 

Yes. Look at the bottom edge of the hatch when it is raised up, and you will see a "U" sticking down. Notice where that U fits into a slot on the hatch floor.

If you can get access to that hatch floor area you will probably find the rear hatch lock mechanism. The plastic trim over that just pulls up, no tools needed.

 

Yes. The repair manual suggests the following test. When viewing the wiring harness connector with the latch on top and the metal terminals facing you, terminal 4 is in the lower left and terminal 3 is in the lower right.

(a) Check operation of the door lock.
(1) Using a screwdriver, move the latch to the full-latch
position.
(2) Apply battery voltage to the door lock and check operation
the latch.
OK:
Measurement Condition Specified Condition
Battery positive (+) " Terminal 4
Battery negative (-) " Terminal 3

Latch turns to open-latch position

 

the weather strip on my hatch sticks and is difficult to open. so much so my daughter broke the studs attached to the outer pull

 

The sticky rubber fooled me when diagnosing an electric door opening mechanism on a minivan. I sanded the door molding with a green scrubby pad to remove the shiny sticky film and it stopped sticking. I would guess the op has a dead motor not sticky molding. Is that a rust spot next to the motor in the photo? Motor is probably rusty and jammed.