Hello.
Using a voltmeter (or a control lamp) check the available electricity between black and blue wires while you lock/unlock the car. If needed use a needle to pinch the insulator and to have contact with the wires inside.
You should have the following:
Locking = Blue + / Black -
Unlocking = Blue - / Black +
1) If electricity not available it seems to be a cable problem.
- 1st check the cables between the door and body, with the door fully open take out the rubber cover.
- 2nd check the same locking/unlocking but use alternatively - from the body (ground). So you'll check + . And then use a + (even direct from battery) and check - from central locking sistem.
2) If you get electricity between black and blue, you have to check the electricity between Blue and White. On the lock is a switch which makes the contact between black and white while the door is closed.
If you have electricity between black and blue but no electricity between white and blue it means that switch is not operating. But door must be CLOSED otherwise it will not work!
Finally, if you have electricity between blue and white (with the door closed) it means either the electric motor is out of order either it is working but mechanical sistem inside the actuator is used.
If you like, you may try another easy way, disconnect the 2 plugs (yellow and blue) and activate the actuator directly, using + and - and connect as I described above. But the door should be closed!
I'll attach 2 photos, one is a wire diagram I did for me but I hope it will assist you. Red in the picture = white in the circuit.
The 2nd one is an opened actuator, I did it 2 days before because I had a problem.
You'll see 1 screw (there are 2 actually but you can see only 1) I fixed the mechanical sistem because the motor working but not always closing/opening..
Hope you'll succeed!