To determine what type of door lock switch you are working with follow these three steps.
Power door lock wiring.
On the above a second 3rd or 4th actuator could be wired in parallel to the first one.
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Locate the harness plugged directly into the back of the door lock switch.
If there are no external door lock.
Basically each wire on the actuator rests on ground and then when the one relay gets activated the ground gets lifted to the actuator and power gets applied to the actuator making it go one way.
This video will show you how to wire relays to control aftermarket door lock actuators.