I bought this house two years ago and never had a problem until yesterday that I turned the air conditioning on and only got fresh air not cool and the thermostad won't come lower than 75 degrees, when I checked the fan outside it was not working. The furnace turns on. What should I check to see if there's somenthing I can do or if I need to call someone. There's a box outside on the wall next to the fan box and a valve comes from it and goes too the inside of the box. What is it? Please advise

The box outside could have fuses in it that blew. The outside unit should have 2 pairs of wire going to a little box inside, the relay or contactor that controls power to the outside unit. The small ones come from the thermostat and should have 24 volts AC. When they do, they should connect the big wires from the house to the big wires in the unit. With the power off at the fuse box, check for the 24 volts on the little wires and conduction between the 2 sets of bid wires. If not the relay is bad. Shut everything dow at the thermostat. Remove the relay, carefully noting where all the wires go. Remove the relay and take it to a electrical supply house and let them match it. Install the new one, connect the wires just like they were, and it should work.

Thank you for your prompt reply. One thing I like to know since this weekend temperature is going down and have not had a chance to work on the fan; will the heater work without the fan? Also if I give you the brand will you be able to tell if the fan has a reset button? My husband was told to look for one..

I am afraid nobody here is familiar enough with the different brands to say if there is a reset. As for the heat, it depends on what type of heat you have, gas, oil, etc. yes. If your system is a heat pump, no. Heat pumps usually are up on legs a little above the ground. Some heat pumps still have gas heat.