My central locking isn't working. The problem seems to be the driver's door. I have now tried to replace the black sender unit (the part where the push rod connects to the loop) 3 times and this has still not fixed the problem. "Most" other electrics are fine on the car. Is there a solution to this annoying problem?

Yes always a solution. You've tried the obvious item, it didn't work so stop changing it. The fault is elsewhere, its not a common fault so you may have to trace the wiring. Are you sure the other motors are working?

All other motors were working until the drivers sender failed

Hi Kelvin.
If the drivers one fails, they all will as it is the one that sends
the power to the others.
Cheers Mark.

Is there anyway of testing if the sender unit works other than in the car.....or how can I check if there is voltage to the sender unit?

yes, the door motors are simple motors (linear), you feed in 12v and they click one way, reverse it and they click the other way.

The driver door units sends out a short 12V signal on 2 wires, the polarity changes according to which way it is switching.

Check the driver door unit is getting power (permanent 12V, pink wire according to my manual) and ground.
Check it is outputting a pulse on the green and yellow wires, the polarity should reverse when you push the switch the other way.
Then check the continuity of the green wire at both ends between the driver door and the say the passenger door. Do the same with the yellow wire.

Do you have a multimeter?

Yep have a multimeter, what setting do you suggest?

Volts to check for volts and polarity, whatever you need to see 12V.

Continuity or diode to check for continuity between the 2 ends of the same unplugged wire *eg between doors

Bulb might be better for the pulsed output, but it won't indicate polarity. Depends how quick your meter is.

Thanks Ride on