Electric door locks - aftermarket

Polarity reversal. They stop using a stall limit just like the windows.

How old is the car? If it's old enough a trip to the U-pull could get you all the OEM parts.

Which is probably implemented in the controller. So buying a whole kit would be a good idea.

I've seen kits which include an r.f. remote. But I don't want another remote on my keychain, so I'll be looking for one with a 12V input from an existing alarm.

The vehicle has a vacuum operated passenger door lock. It slaves the passenger lock off the drivers door. But that's still key operated.

Depends on the system. GM actuators have the limiters in the motor units.

If the existing system has split controls you could just use GM style units and a couple relays one would be straight polarity and the other reverse polarity. I would test it by connecting a test light to the outputs and see what happens when you push the button. If you hit the button and get a 1-3 second pulse the relays should work

My name brand alarm, which I installed but whose name I forget right now but they're very big and do almost nothing but alarms, only sends a pulse, one of two lengths. I use the shorter pulse because I have factory door locks. I can check how long the second pulse is.

P&M because I'm so late.