2000 Chevy Silverado Driver side power window

At the switch, check that you are getting power on the dark green wire from the fuse, it is pin F, and can be checked with a test light. Another check is for ground at pin M black. If you use a test light and go from pin f to pin m and it lights, you checked both circuits. Pins a and m at the switch connector are for the left front power window functions. Pin A is dark blue, and pin f is brown. At the switch, when up is commanded, pin a will have power, and pin M will have ground, and vice versa when commanded down. If you have them at the switch, check at the motor. If you don't have them at the motor. If I had to guess, I would say you probably won't find power or ground on the dark green, or black wires at the switch. If that is the case, you will have to trace the wiring back to find a break. On vehicles with higher miles, it is not uncommon for wiring to eventually fail in the door pivot pass-through.