Central locking confusion... Fixed thanks

[Awarded]

Looking for some help with my central looking.

I should preface this by saying i am using my spare key because the main key was bent by the PO and doesn't work. Also the car has an aftermarket alarm fitted that doesn't work.

Unlocking the car: The drivers door will only unlock itself. Passenger door cannot be unlocked by the lock in the door, it is only unlocked by unlocking the boot, having already unlocked the drivers doors.

Locking the car: All doors can be locked individually. Locking the drivers doors locks both doors and the boot.

I don't really understand why the drivers door can lock the whole car but not unlock it. Thanks in advance

[Brianmoooore]

Remove the driver's door card, slacken the two screws that hold the lock motor in place in slotted holes (half way up the rear of the door, just covered by the card) and see if moving the motor in the slots changes things.

[Awarded]

Thanks, I'll give that a go.

It's an '87 m-tech 1

[Awarded]

I've just tried the central locking with the motor slid all the way up and down and a few place in between but doesn't seem to have done anything.

How far should the key be turned to open the car? To lock I turn the key from 12 o'clock position to 9. To unlock the key only turns from 12 to 1:30. Is this correct or should it be going to 3?

[Brianmoooore]

Doesn't sound quite right. Flip the large C clip off that holds the lock barrel in place, pull the barrel out, and check that the 'over centre' toggle mechanism for the alloy L shaped piece on the back is working as it should as you turn the key. The hinge tends to seize with hardened grease.

[Awarded]

I'll have a look at that. Thanks

Could it be a wiring issue? A faulty connection in the passenger unlocking micro switch or similar?

[Brianmoooore]

The locking ECU has two lock request inputs and two unlock request inputs. One pair is used by the doors and the other pair by the boot, so it's possible you could be onto something.
I've looked more closely at the OP, and see that neither door will unlock the system, so there is no unlock request signal reaching the ECU on the green/blue wire.
The boot lock sends the unlock request on a yellow/black wire, and that is working as it should.
The absence of signal on the green/blue could be because neither switch is working (both part of the respective lock motors), one of the switches is permanently earthing the wire, the locking ECU has failed on that input, or the defunct alarm is permanently earthing the wire.
Dig the locking ECU out of its hiding place in the sill under the driver's foot well speaker, and without disconnecting it, use a piece of wire to momentarily earth the green/blue wire with the locks set. A convenient earth is the brown wire on the same plug.
If things are working as they should, all the locks should unlock. If they don't, momentarily earth the yellow/black and confirm that unlocks all the locks.

[Awarded]

I've tried earthing those two wires and they lock/unlock the passenger door and boot. Neither activates the drivers door. I've just replaced the C40x connector in the passenger door due to corrosion so I think I'll test the drivers side connector for the central locking wires and some of the connectors look slightly corroded. Is the a way to remove the connector pins from the plug housing? For the passenger side I just had to rip apart the plug housing with some pliers, but I don't want to replace all the pins for the drivers side as well.

[Awarded]

The voltages for the microswitch wires in the door connector are:

unlock microswitch wire (green/blue) - 9.2 volts when doors are locked by grounding the yellow/blue microswitch wire, 0 volts when doors are opened by grounding green/blue microswitch wire. (this isn't locking/unlocking the drivers door still, as previous post)

lock microswitch wire (yellow/blue) - 9.6 when doors are locked and unlocked by grounding the respective microswitch wire.

What are they meant to be? Is there a way of testing the drivers door motor because i don't know if it works, and the microswitch won't activate it, unlike the passenger door.

[Awarded]

Should I replace the central locking control unit?

[Brianmoooore]

If green/blue and green/purple both unlock at least one lock, and green/black and yellow/blue both set at least one lock, there is nothing wrong with the locking ECU.
The wires to all the lock motors are white and blue. Applying 12 volts to them for half a second with positive and negative applied one way around sets the locks, and doing the same with the wires connected the other way around unlocks them.
The deadlock motors in the passenger door and boot lock are controlled by the black wire and the white wire. If 12 volts is applied one way around to these wires for half a second when the locks are set, the dead locks should engage, making the passenger actuator impossible to move. Applying the power the other way around should make the actuator moveable again.
The tests above must be done with the locking ECU unplugged, are are easiest done by using a short piece of wire to link the red/black to one of the wires in question, and another piece of wire to link the brown wire to the other wire.
The driver's door and the boot are locked and unlocked by switches built in to the lock motor assembly. The passenger door is locked by the microswitch behind the lock barrel, but is unlocked by a switch built into the lock motor.
The microswitch behind the driver's lock barrel is for the deadlocks. When it is open the deadlocks are not set. When it is closed the deadlocks are set, and the unlock signal to all the locks on the white wire is blocked.
The control circuit for the lock motors is digital, using logic levels of OV and 12V, so voltage measurements are irrelevent.
If the driver's door lock motor doesn't work from the blue and white at the ECU plug, apply power directly to it, or to the wires in the A pillar plug.
Check that a 55W headlamp bulb will light at full brightness when connected to the red/black and brown wires of the ECU plug.

[Awarded]

Thank you Brianmoooore! Got my central locking working.

[Brianmoooore]

So what was it?

[Awarded]

Slightly embarrassingly, when i dismantled the door and went to power the motor directly i felt for the wiring and the connector wasn't properly plugged into the motor so i pushed it back in and it worked. Sorry for wasting your time

[Brianmoooore]

Many faults DO turn out to be something as this, and it's not been a complete waste of time - you've learnt a lot about your car's locking system along the way.