The fan that blows hot air/cold air all of a sudden wont turn on when you hit the switch..the 30 amp. Fuse is good. How do I rule out whether its the switch or the fan motor.

Testing the electrical circuit before replacing parts is how it's suppose to be done . The blower doesn't work at any speed ? Did you check A/C FAN fuse 20 amp in the left instrument panel fuse box ?
Blower Motor Problems Auto Repair Help

Low coolant, if there is an air pocket in the engine it will make it to the heater core. Once there , the air coming out is cold/cool. Once the coolant fills the heater core, it gets hot. If the coolant is fine hot or cold, then have the HVAC system scanned.

charge with freon

Someone will need to find out if the compressor clutch is failing, or if it is loosing power due to a pressure switch or other problem.
A faulty relay or switch could get hot and switch off power to the compressor.

I have a 2000 pontiac grand prix with a digital climate control system. The heat quit working, it doesn't blow out any heat. Now that it is warm outside the air stopped blowing out any air. The digital temperature on the climate control is not correct. When it states that it is below 30 degrees on the ext and it is warm outside the air wont be cold. Once it starts going above 30 degrees the air gets colder. Today the blower stop working all together. Was told it maybe the climate control unit was bad. You can hear the door opening/shutting when you switch the temp from cold to hot. But there was no heat blowing out whatsoever in the winter time. Could you please give me your opinion on whether or not it is the climate control unit or something else?

Behind the temp panel the wires or hoses are back words

WELL TURN ON AC MAX COLD HIGH TO SEE IF COOLANT FANS TURN ON.IF NOT YOUR REFRIGERANT SO LOW THAT THE AC REFRIGERANT PRESSURE SENSOR WONT CLOSE CIRCUIT TO TURN ON COOLING FANS.MEANING YOU NEED HAVE AC CHECKED AND CHARGED.ALSO CHECK COMPRESSOR FOR POWER IF NOT YOU HAVE BLOWED FUSE OR BAD RELAY.IF FUSE AND RELAY GOOD YOUR AC COMPRESSOR CLUTCH COIL OPEN OR THE AC CONTROL SWITCH IS BAD.IF COMPRESSOR IS RUNNING WHEN YOU TURN ON AC YOUR AIR TEMPERATURE ACTUATOR NOT WORKING.

possibl ac compressor clutch problem,cooling fan at rad not working so ac goes into high press mode and turns off(so it doesn,t blow system apart,built in safety)not enough r134 in system(low charge)

expansion valve looks like is not openning or the capilary tube is bad

after checking the heater core hoses they were both hot I went in to look at the blend door and noticed it wasn't moving on hot or cold so I simply disconnected the lincage and moved to hot and its working ok. but its not completely repaired