Rewiring automotive central locking

Thread Starter


Joined Nov 8, 2015
Okay -- attached is the wiring diagram.

The goal is to rewire it so it operates from a remote fob. Why? because replacing the module is darn expensive and it could be fun to learn more about electronics.

First though trying to understand how i'd wire it from just a switch.

So if the motors was two wires i'd be thinking DPDT (?) switch... but as per the wiring diagram attached it's three wires. I think this is basically the same but the module controls which earths and which powers depending on unlocking or locking motion.... but how would I wire this in...

If I can work out how to wire one motor, I can then move on to integrating all 4 motors, then move on to not just the switch but also a remote fob... should be easy enough if a switch is installed I think..? a relay and a paralel wire across the switch...

Not after you all to do all the work guys... just tips or links to relevant reading literature or components to research etc....



The schematic said typical. Let's concentrate on circuit #90 only. In your diagram, the switch is integral to the motor. The switch makes it IMPOSSIBLE to run the motor continuously. I can't tell which wire would go to+12 or ground.

But, SUPPOSE the motor is connected to +12. Then you can ground (pulse) the exposed terminal of the internal switch, one at a time and IF, it's the right one, the lock will move. e.g.If the lock is locked and you applied a lock pulse, the motor would not move. THE LOGIC MAY BE REVERSED.

You might find it easier to just parallel the switches that operate the motors. You have lock and unlock and a lot of times you can just "DIODE OR" the logic, so all doors lock or unlock with a LOCK and UNLOCK relay.

LOCK and UNLOCK are usually one switch. In one vehicle, the driver and front passenger can lock/unlock all doors.
The rear passenger have to use the mechanical locks, but they do have electric actuators.

I think there may be some "child safety" options that might be able to be programmed, but not sure.

I had a two door car and I installed a switch that would UNLOCK the passenger door only if that switch was on.

Another use of a DIODE OR in that car was a "Headlight on reminder". My remider worked like, If the "driver's door was open and the parking lights were on, the buzzer would sound.

I'd locate one of the lock/unlock switches and work from there. Installing Two bosch relays in the door panel might be the easiest option.