Hi, I've been having a problem with my A/C coming on in an upstairs unit. It is in the attic.

I've changed the batteries in the thermostat, changed the filter, changed the capacitor, checked to see that the blower motor is working. (I removed blower motor and jumped it with an old electrical cord and it came on)

My problem is; the outside unit comes on, the upstairs unit has a low "squeaking noise" the A/C going into the upper part of the furnace, but the blower does not come on. When I put the blower motor back in and hooked up everything back up, it actually started and air was blowing out the vents! But, it was short lived. :( The air coming out was not very cool. I don't understand why the A/C keeps going out? Any help would be GREATLY appreciated.

Thanks so much!

Sounds like the bearing in the fan or the motor are worn or frozen. Is the fan belt driven of direct drive. If belt driven, the frozen bearing is probably in the fan itself. Try lubricating. If lubricating doesn't work you will probably have to replace fan. If belt driven the belt could be to loose or worn. Remove belt and see if you have the squeeking noise. If fan and motor manually turn freely the problem is probably a loose or worn belt.

If the outside unit has been running without the air handler in the attic operating properly, the coil in the attic is probably iced up. Leave everything off for a while to let icing melt.