Help! It's 86 degrees in the house and I have two kids and wife and the darn AC unit won't work.

Here's our situation.

We own an older sears Air Conditioning Condensing Unit (Model 867.816850) that sits outside our house. The furnace is a separate unit that sits inside the house. When the system is set to cool and the temperature lowered to 78 degrees... the furnace (fan inside the house) comes one. BUT... the outside air conditioning condensing unit won't come on. The fan doesn't spin... and it makes this humming noise. I took a stick to try and move the fan. It moves freely. Is it a bad motor? There's power to the unit. What could be wrong?

Next question is... if we were to replace the condenser unit alone... what's the average cost to replace? What about average cost to "recharge" the existing system with new refrigerant?

Thanks!

It's Hot Here!