I was putting on a new thermostat and everything didn't work the way it was suppose to. So I tried 2 other thermostats and wired them the same exact way and got different results for each. How that makes sense I have no idea. For some examples fan on would make me lose power to everything the blower fan inside and outside would never shut off and I would have to kill everything at the breaker when I was done with the air. Its a mess in the furnace wire wise and my buddy and I have been trying to make sense of it all to get this to work with no success. Im ready to call a service tech but im afraid of the bill.