Rebuild or replace power window motors in 1989 Mustang GT
My passenger side power window (89 GT) is acting up. It will roll down well enough, but when I go to roll it up, it's sketchy at best. It won't respond immediately. With the button depressed, the motor won't run, but the battery guage in the dash registers a dip, indicating there is power being applied to the motor. If I hold the button for a while, sometimes it will respond, or sometimes I need to tap the switch repeatedly to get it to work. Once it moves, it's fine, going up or down. It's only when I leave it down for more than 5 minutes that it starts misbehaving.
Is this an electrical demon, or is it the motor itself? If it's the motor, can I rebuild it with the eBay kit, or do I have to replace the motor?
'89 GT, 5-speed (because it's boring when the car does it FOR you), GT40 heads, Performer upper and lower intake, Comp Cams camshaft, 75mm MAF, 30# injectors, 70mm throttle body, K&N, 3G alternator upgrade with Taurus fan and DCC fan control, subframes, Cobra R 17X9's.
Engine bored 30 over, and rebuilt after 310,000 miles.