I just bought a 2002 Ford Explorer Sport Trac and neither (driver or passenger) of the power side mirrors adjust. Any suggestions? Could this be just the switch or the motors. I am assuming that there is a motor in each mirror. I have checked the fuse and that doesn't seem to be the problem. Any help appreciated.

It's likely the switch itself or the wiring going to the switch. Normally, both motors won't fail at the same time.
If you've check the fuse (F2.16 is a 5amp) in the Central Junction Block (CJB under dash panel, LH side) the next step is to check the power going to the switch.
Check for power (hot at all times) on the OG/LG (orange w/ light green trace) wire going into the exterior mirror control switch. You'll also need to verify that switch has a proper ground. That is the BK (black) wire.
Connet your voltmeter Negative lead to the BK and the Positive lead to the OG/LG and you should read near battery voltage.

See what you get and let us know.

Thanks for the info. I'm assuming I will need to open the door panel to get to these wires and the switch. I saw those instructions somewhere. I will try that when I get home tonight and I'll post back my results. Thanks again.

Don't overlook the mirror slide switch. To control the left mirror, the slide switch must be to the left. To control the right mirror, the slide switch must be to the right.

Thanks for the expert help. I removed the door panel although I discovered the switch just pops out so removing the whole panel was unnecessary (although I now know how to do it) and was able to test the power to the wiring as suggested. There WAS power so I got a replacement switch from my Ford dealer, installed, and now my power mirrors work great! Thanks for the help!