The locking wires in the ST come from relays that are configured in a ‘toggle’ fashion. This means that at any one time the locking wire will be connected to either ground or +ve. The locking wire is never left ‘floating’ ie not connected to any polarity.


To lock all doors; +ve is applied to PIN 2 (yellow/red on drivers door, yellow/green on passenger). PIN 4 (double locking wire) and PIN 10 (unlocking wire) are resting to ground at this point.

When the doors are locked the motor spins to the locked position and in doing so catches a switch. This switch, when pressed, flips the connection from one side of the motor to Pin4. One side of the motor is connected to Pin10 whilst the flipped side is connected to Pin4, with both pins being at ground. This stops the motor progressing any further.

To unlock all doors; +ve is applied to PIN 10 (white/green drivers door, white/red passenger side). At this time the other side of the motor will be connected to Pin4 (dl wire) which will be at ground. Pin4 is momentarily used as the grounding for the motor. Pin2 (locking wire) will also be at ground and will connect to the motor as soon as the motor moves off from the “locking” switch, keeping a closed circuit thus making the motor fully wind round. The motor will continue to try to turn for as long as +ve is applied to Pin10.

To set deadlocking; when the doors are locked, +ve is applied to Pin4 (deadlocking wire). At this time Pin2 & Pin10 are at ground.

To unset deadlocking (while still keeping the door locked); Pin4 (deadlocking) goes +ve along with Pin10 (unlocking). Pin2 (locking) remains at ground. This moves the motor from deadlocking position where it is connected to Pin2 & Pin10 across to the switch where the motor is connected to Pin4 (+ve) and Pin10 (+ve), halting it at locking position.