How can I (or, can I) test the blower motor/regulator without pulling the wiper assembly? I have no operable blower and I don't know if it is the head unit or the regulator or the blower motor itself. Can I isolate each one without pulling the motor. I realize that to check the head unit (the dash module w/ the push buttons) I'll need to have a mechanic use the appropriate tester.

Intruder