The relay for the drivers window is internal of the GEM module so if you have a bad relay you would have to replace the GEM.
Do you have a 12V test light or voltmeter to check with?
Here are the wiring schematics for the window motors to help you out.
In the down position you will have power on the WH/BK wire on the right and ground is provided by the GEM on the other wire. It will reverse this in the other direction.
Is there a relay for the power window?
No it is part of the GEM module,see the first page of the schematics. This is what works the one touch down on the drivers window.
Is just the drivers window inop or is both?
Ok look at the 2nd page of the schematics for the passenger window.
C and D is the power feeds and E and F is the ground.
As you can see everything goes thru the drivers master switch before it goes to the passenger switch except for the pink wire on pin 8 of the passenger switch.
So even if you use the passenger switch your ground still has to come from the drivers master switch.
When you press the switch to down you should have power on the YE/RD wire and ground on the RD/YE. It will reverse when you go up. Check this at both the drivers master switch and the passenger switch.(the GEM is not involved on the passenger motor) So you either have a bad switch or a broken wire.