My unit want come on from the thermostat, model number FEBB-012HA. My heat works fine but when I call for cold nothing happens. My fan inside want come on when I put it in the on position either(thermostat). So to run ac unit I press in the contactor and cut the fan on manual to cool the house. The ac unit and the fan went out a the same time. Replaced cooling relay didn't help.

You cannot be a "parts changer" and fix an AC unit. It does not work and never has worked. Get a meter and test the different parts. Here are some manuals: https://dl.dropboxusercontent.com/u/8010163/AC%20Wiring%20Diagrams.zip
https://dl.dropboxusercontent.com/u/8010163/How%20to%20use%20Test%20Equipment%20Service%20Manu al.pdf