Ac condenser fan comes on but shuts down after about 20 minutes or so, followed shortly by compressor. When power is off fan spins freely and capacitor isn't bulged out. Can you tell me my problem, PLEASE?!

Ac condensor fan comes on but shuts down after about 20 minutes or so, followed shortly by compressor. When power is off fan spins freely and capacitor isn't bulged out. Can you tell me my problem, PLEASE?!!!!

It could be the motor is overheating caused by a weak capacitor or a dirty condenser (outside ) coil. It could also be that the motor internal overload has been weakened over time which would mean that the motor itself could be defective or loose wiring. Sorry but that is the best I could do from here.