My Lantis has a 5 wire drivers side central locking actuator.
After many years of the Central locking not working I decided to fix it.
The only thing broken was the Drivers side Master actuator which in the case of my car was a 5 wire system.
Two of the wires are for the motor and the other three are for the two position switch for unlock or lock.
On measuring the resistance (ohms) across the motor I found a reading of 60ohms and on measuring the switch I found that OPEN.
Removed the side cover and found. (The soldering is me)

Photo 2 shows the inside of the actuator.
Section 1 shows the contact's for the switch.
Section 2 shows the plunger and the soldering I did.
The contact leaf's each side of the plunger needed to be soldered together.
The leaf contacts also needed to be bowed out a bit to ensure a good contact with the plates that run up both sides of the plunger channel.

Reassembled unit (Plunger must be installed the correct side up)
Check that the switch works. (Move plunger with the meter connected to Earth (black) and either blue or Green/White.
Readings should be OPEN to SHORT or the other way round).

The third photo shows you the contacts for the motor.
I found by giving the motor terminals a small twist they connected to the motor better and the meter reading was 4-5ohms)
I then put it back together (bit of sealant to stop water getting in the unit) and checked that the switch/motor were good.
Worked really well.
Hope that was helpful and not too confusing.