96 grand am power door lock problem

I have a 96 grand am se. The power door locks will not work (driver or passenger side). The doors lock when I drive and unlock when I shut the car off. I tried switching out the relay under the dash with three others I got at a jnkyard, I don't think four different relays would be bad. Is there a way to test the switches themselves? I have a multimeter but have no idea how to test for continuity (as I have seen suggested elsewhere). Also checked for voltage at switch, got four volts (unsure if I did this correctly). I don't want to buy switches and have that not be the problem. Is there a way to jumper the switch wires to test? As I said, the actuators work or else the door would'nt lock or unlock when driving and stopping. Any help would be greatly appreciated.
Thanks Rich