When this happens it usually means that the motor is gone. It happened to my 85' 5.0 and I went to the guy that does all of my stereo and car electronic stuff and he fixed it. So its either the motor is weak and needs to be replaced or it could just be a fuse. I would check the fuse box to be sure.

 

it tries to open, it clicks, but it can't.. also, could it be the alternator? cuz i can hear it when i start the car, it's whining a high pitch sound.

 

Yea its probily the acuators but before your get new ones take your door panels off and use a test light or multi meter to check for power ant the conector. but both acuators on my moms 90 stang went bad and i just disconected them

 

yea i didnt want to mess with taking off the door panels, are you sure it cant be the alternator? it is bad too..