I have an old carrier 58gs075-3.
After months without use the A/C was turned on.
The unit appeared to function normally and cool the house,
but the internal fan (air handler?) stayed on after the compressor
shut off. Had to unplug unit to get it to turn off.
Research showed that the CFR (fan relay) was probably stuck,
so I replaced the control board with the icm271. All seemed to
work fine for a few minutes. Plug in unit and no fan. Turn on
thermostat and fan turned on and compressor kicked on and
air came out. goody problem seemed to be solved.
Then a click of somekind and the compressor turned off and
the int. fan kept going, but no cool air and no compressor to
cool. Worse than when I started.
limit switch is closed
fuseable link is closed
fuse on icm271 is closed
Any other tests I can perform to see if it is the transformer now
or is the outside fan/compressor failing now?