Outside condensating unit continues to run
Lately I've noticed that the outside unit continues to run with no heat coming from the vents. When the thermostat clicks, the heat starts and will continue to run until, of course, the set temp is reached, but the outside unit continues to run, even after the temp is reached.
After some searching, I was sure it was the contact block that's supposed to be located in/at the outside unit. But I ran across the suggestion to turn the thermostat to "off" and if the fan stopped, it was more than likely something to do with the control wiring.
After a flick of the switch, viola! the outside fan stops. turn the therm back on and the fan doesn't start again until the next cycle, then the fan continues to run.
I would appreciate any/all help as to where to start looking at this control wire. Could it be the thermostat has gone bad? How to check? Could it be some creature has invaded the crawl space and chewed through some wiring? Could it still be the contact switch at the outside unit? My reading has indicated this should be less than a $20 DIY project if so.
As you can tell, I'm stuck and in our area, decent HVAC people are few and far between, then coupled with a holiday, even more so. Any help will most definitely be appreciated!
If it helps, the unit under the house is a carrier and the outside part is a Bryant...........