Need Help...Outside unit will not shut off
Hey all....I have a problem with my outside unit not wanting to shut off. I just recently graduated from an HVAC program, but I am stumped as to why my unit will not shut off unless I switch it off of cool from the furnace. For some reason when I switch the thermostat off of cool, the outside and inside units will not shut off. I can turn the temp above the temp in the house so it will kick off, but it wont. I have even turned the switch on the furnace off of cool, and tried to just run the fan in the on position and it will not kick on...the only way I can turn on and off my unit is to use the switch on the furnace.....I am completely stumped as to why it is doing this...I have even went out and check the contactor...and it seems to be working fine. Can anyone help me out.