Hard to say from miles away.

I always ask...what is age of system and when was a routine PM last performed?

Could be thermostat or some type safety lockout. I suggest monitoring system closely and if it happens again, call for service from a qualified dealer not a hack.

IMO

Did the air handler fail on start up? If yes it could be a start capacitor. It could also be a relay or the blower motor could be failing.

Thanks for the input. I think it is about ten years old. After I got it going, I have left the air handler fan on and so far so good. I will get it checked tomorrow. My usual guy is very good but was not available this evening.

Turns out the unit is 13 years old and has a two speed blower motor that has gone out. The thermostat is fine and there is no capacitor. The big company wants a flat $1,000 to change the motor unit, oem. I am getting my regular guy to put in a new motor for $500 and plan a replacement of the whole thing this winter after careful research. I can't see paying $1,000 and I don't want to rush into an expensive replacement. The new motor will not be a two speed, but it will cool the house for a while. Around here the lows will be around 80, with high humidity for months from now.