Hello to anyone that may be able to assist. I am an automotive/exotic car shop owner that pretty much is willing to repair anything. I have repaired several of our AC units over the years but am not trained to do so.

My wife recently asked me to install a programable thermostat (hunter)

I have installed the same one on the downstairs unit years ago.

After installing it exactly the same way as the first one with the exact same wires at hand it does not cool. I also noticed that the fan is staying on no matter what even with the thermostat removed. My wife informed me that this had been going on prior to me touching anything but she forgot to tell me. The only way i can shut it down is by pulling the breaker or by pulling the fuse on the circuit board. After powering it back up there is an approx. 15 sec. delay before it kicks back on. I suspect a bad circuit board. I cn hear the relay kick in when it comes back on. My wife thinks the AC worked before switching the thermostat but as it is just now warming up that may be a false statement.

Thank you for any advice.

Karl