All, I need some help in where to start troubleshooting issues with the power locks on a 99 (2000 bodystyle) silverado. Neither power door lock works. I can manually lock and unlock both doors just fine. when I press the L or U I do hear the relays click in the fuse box. I have the covers off of the fuse boxes and have checked all the fuses that I figured were part of the power locks.... So I am not sure where to test.. I have the door pan off. I see I have 3 elec plugs that go to the door lock assembly. One of the plugs has 12 volt on it. It does not change when the L or U is pressed. One plug is for the door buzzer and the other one I assume is the switch... I am not sure how to test that? Can you guys help?