You can go to the local auto store and get a repair manual for your vehicle, if you don't have one, the wiring diagrams might help you, to understand the system.
Right now, I would probably pull the electrical connector for the blower. You might be able to just pull a fuse. By killing the circuit, it might allow something to reset, then it might work normal. I don't usually get that lucky, though.
Some automatic temp control systems have their own diagnostics, with obd11 you might need a manufacturers scanner to get the info. OBD1 usually you could press a couple of buttons on the control module, to get info.
If you don't get an answer you like here, you might try allpar.com, that is a Dodge--Chrysler--Plymouth site, they have Q&A forums.