I have a 15 yr old, 4 ton York AC in mid-atlantic. We have an extended warranty. We've only started having problems in June. I have had a service guy at my home 8 times and its going on three weeks.
Here is status:
Warranty replaced compressor (with Copeland) last week.
Capacitor, relay, and Condensing fan motor replaced over last two weeks.
Condensor fan stops after approx 15 min when AC turns on. Compressor still runs. I initially heard strain and turned off at thermostat.
This fan issue started after the new compressor was installed (week ago). Fan then replaced,days later, but also has same issue.
Service technician does not know cause. Has stood with me (twice) to watch fan stop and compressor continue after approx 15 min run time (inside house temp 80+, so never got down to comfortable range (75-78).
Only thing I noticed was that the capacitor was initially 50 amp, and was replaced with 80 amp. Technician said that should not be an issue. Thermostat is 15 years old also. Mecury. Going back into 90's this week. Technician has been here 4 times just for fan. Would like to provide guidance, if have any. He had switched contact points on capacitor (thinking that would solve, but did not).
Currently, go out every hour or so and turn on for 10+ min, then off, before compressor strains. At night, fan only. Advice?