Air Conditioning - Condersor Fan Motor Trouble

Have a 25+ year old American Standard central air unit. Recently had to replace the condensor fan motor. The HVAC tech replaced it with a similar motor but with a little higher RPM rating along with a new capacitor to match the new motor. Since replacing the motor apparently is throwing the thermal protection switch after running for about 20-25 minutes. The fan motor gets extremely hot to the touch, i.e. makes you jerk your hand back upon the slightest touch. The compressor keeps running for a minute after the fan cuts out before it stops. HVAC tech came back out the next day and realized he had not removed the old capacitor for the previous motor (mounted in another location on the cabinet) thinking this was the problem. Well, after he left it still does the same thing. What else could be causing the fan motor to overheat? Could the new capacitor have been damaged by having the old one still in place? I have noticed too that the compressor capacitor had a lot of corrosion around the connectors and some whitish looking crust all around the bottom of it (it is cyclindrically shaped with the connectors on the bottom). Could this affect the fan motor even though it is for the compressor? The tech has not been back out to take look (over a week). The fan motor still starts and works OK after I let it cool down. The A/C unit still cools very well too. I just don't let it run too long so as not to over heat the motor. Thanks for your help.

Sorry to say at 25 years old Let it go and get a new AC unit here. Fan motor over heat??? same HP????. Also think Id get a new hvac tech to work on it. A new unit with a higher SEER would pay you back here Ill bet.

ED ;)

Thanks for the advice but I don't have the moola to drop on a new unit. I just want to get the fan motor up and going again like it should be and then I will start a savings fund for a new unit. So got any ideas on the original trouble shooting issue? Thanks.