I have a York split system heat&air unit. The blower motor does not run on A/C. It does run in the fan only position. Also runs with heat. I pulled off one wire on the capacitor mounted on blower housing and motor would humm but not start, but ran again with wire replaced. The top fan and compressor come on. Just no blower with A/C. No noises or warning, worked fine yesterday but did not come on this morning. What do I need to look at or eliminate next. Thanks Ed

Bad thermostat , we are talking indoor blower ? Correct? The thermostat will turn it on when put to the "on" position but not in auto ? That's the thermostat. Mike
By the way is this a Honeywell mechanical thermostat?

I agree, sounds like it's the thermostat!

I have a York split system heat&air unit. The blower motor does not run on A/C. It does run in the fan only position. Also runs with heat. I pulled off one wire on the capacitor mounted on blower housing and motor would humm but not start, but ran again with wire replaced. The top fan and compressor come on. Just no blower with A/C. No noises or warning, worked fine yesterday but did not come on this morning. What do I need to look at or eliminate next. Thanks Ed
Thanks guys and yes it is an old Honeywell made around 1825 I think. So I'm off to Wally World or Home Depot to find a tstat and hope it is as easy as that. Ed

Be sure to unplug the furnace before changing thermostat, don't want to burn out the transformer.