I threw away the furnace in 2010 keystone Springdale that is a permanent fixture on a lake lot. I did not use the furnace, it had a mouse problem, and I like the added space I got from removing the furnace. But now ac won’t turn on. I have read similar internet posts pointing to power to the thermostat as the cause of the problem. But, how do I fix it? Where the furnace had been I have 1 red, 1 yellow, 2 blue wires. Red has voltage…I touched red to yellow and blew fuse at converter box. Can I just work with these 4 wires to get thermostat and subsequently the ac working? Or do I need to tap into another 12v power source such as an outlet?