I have a Worthington mueller Climatrol model 171-130
Cooling cycle runs until furnace blows cool air, to long I think. Can I shorten this cycle?

You may want to do a search for a manual for this unit and see if there is a time delay for the fan that can be adjusted. They are usually temperature controlled... a snap disk at a certain temperature or thermostat.

Would you know where I could find a fan limit switch for Worthington mueller Climatrol model 171-130?