What is wrong with my Door Locks besides the switch itself? on 2000 GMC 3500 Pickup

I replaced the master door lock switch and that did not help, still all 4 door locks are not working. What besides the master switch could be causing all 4 door locks to not be working?

Asked by for the 2000 GMC 3500 Pickup
1 answer
check for power and ground to the switch