OK so my problem is this, I had my air on the other day and turned it off for no more then 1 hour so I could air out the house went to turn it back on and nothing. My unit outside will come on but no fan. I did a few basic checks that made me think it was the thermostat so I changed that out( pretty sure that I hooked it up right, couldn't find the model number online so I used the cross reference in the pamphlet with the new thermostat).

First check was trying to turn the fan on (didn't turn on), second was try the ac again(still nothing), last was turn the heat on(that did turn the fan on and blew hot air). What could be the problem, and what should my next step be?