I asked this question earlier but wasn't as specific I have a 2000 Lincoln Navigator AC was fine yesterday I went to use my AC today and the blower motor wont turn on the AC pump works fine but the blower wont even kick on for the heat I tested all fuses for it there all good I unplugged the blower tested the plug and it had no power I'm pretty car smart so if sombody could please help me out to get it working again I appreciate it I am aware that the heat/cooling head unit could of just went bad but the chances of that over night seem slim
first, did you test each spot for available voltage while the car was running with AC switch on? if you did it all while the car was turned off you'll get false readings, keep looking through the whole circuit and once you find available voltage in between that n where there is no voltage you'll have to visually find the open, another problem could be that you have a refrigerant leak somewhere, the ac refrigerant can leak out in one day if it's bad enough and if you have no refrigerant in the ac system then the ac magnetic clutch won't even turn on because the pressures aren't high enough so you would get no voltage in the AC circuits because pressures aren't high enough for the ac system to kick on
I am aware that the heat/cooling head unit could of just went bad but the chances of that over night seem slim -- Not really. That EATC unit definitely could have gone bad over time and last night was its final hurrah. 13-year old electronics can get crusty. Good luck there, because that's not a cheap piece of electrical machinery to deal with.
