Remote Central Locking Problem

[barrass 0]

Can someone please explain how the remote locking system works on phase 2 car,the remote seems to be working as when it is pressed there is a volt drop on the live wire on the 3 pin plug (drivers side) and the 2 pin plug is live on both connecters,the motor works if connected to a battery on the 2 pin part but does not work on the car ? is it just a fault with the drivers motor not switching ?

[Slo 283 1 Cars]

Check the wiring that goes through the door rubber. they are prone to breaking especially in winter time when they are frozen solid and brittle. Could be an earth problem