Good the switch is ok though.
How it works is like this :
1. When the door opens, the Services Unit ( N82 ) detects it via the switch on the lock.
2. If there is no earth signal on pin A7/B12* ( depending on which door is open ), the controller starts the window motor to drop the window. Whilst it does this, it continues to monitor A7/B12 as appropriate.
3. When it detects an earth signal on A7/B12, it stops the motor ( the microswitch roller has moved far enough along the cam to alter the state of the microswitch ).
4. When the door is subsequently closed, the controller detects the change of state of the door open switch.
5. If pin A7/B12 is connected to earth, it switches on the motor to lift the window.
6. The motor stops going up by the normal current sense method as used when a finger is on the switch.
The controller also recalls whether it was responsible for lowering the window or not. So, if the window had been manually lowered prior the door being opened, the controller detects there is already an earth signal on A7/B12 and doesn't lower the window any further. When the door is then shut, it knows it didn't lower the window so it then doesn't attempt to lift it again.
Don't put 12v on the microswitch wires! At best it'll be pointless. From my description above, you can see why.
I would proceed in three ways from here.
1. Remove the cam altogether. Hold the microswitch roller in against the microswitch. Open the door. The window should start to fall. As it does, release the roller and the window will stop ( probably about halfway down! ). Don't use your finger - too much risk of slicing it off. If this test works, it really is just a matter of adjustment.
2. With your continuity tester, test the black wire from the connector you tested before to the car body. Not the door frame - it may not be a good earth to the car body. This is unlikely to be the fault as all other door functions are working. But it does test the bit of wire between the connector and the rest of the door loom to the car body/earth.
3. Remove the glovebox. Disconnect the 'A' and 'B' connectors from the Services Unit ( N82 ).
Have a look at this photo :
The white connectors in the middle of the picture plugged into the black box are the 'A' ( larger ) and 'B' ( smaller ) ones you're looking for. Your controller is probably purple, not black and will be mounted slightly differently to the one in the photo. The casing at the bottom left is the round heater fan housing. The connectors have a latch ( not visible ) but it is identical to the unrelated connector at the very top of the photograph. Press the latch and the connectors should come free.
The microswitch wire in your door will either be Green/Black or Blue/Red ( look at the connector you've been testing ). Find this wire in one of the connectors behind the glovebox. Be careful in respect of the Green/Black wire as there will be two of them. One is used by the window switches. If in doubt, look very carefully at the connector shells and you'll see tiny numbers moulded into the plastic where the wires enter the connector. If the Green/Black wire doesn't match 7 ( on the large 'A' connector ) or 12 ( on the smaller 'B' connector ), you have the wrong one. The Green/Black wire you don't want
should be connected to A2. Again, using a thin bit of wire on your continuity tester to access the terminal in the connector, connect the wire behind the glovebox and the other side of the tester to the car body. Making sure, the connector in the door for the microswitch has been reconnected, check the continuity by operating the microswitch manually. With the roller pressed to the microswitch body, it should show no continuity, with the roller released there should be continuity. If you don't get this, you have a wiring fault.
Let me know how you get on. If this doesn't prove anything, there's one more test that can be done to test the controller itself.
* A7/B12 are the two pins on the Services Unit ( N82 ) that the autodrop microswitches are connected to.