I have a 17 year old Trane 3.5 ton unit (model TTP042C100A4) that has developed a problem. The outside unit starts but the compressor eventually quits. I had my trusted advisor over who looked at the unit and said the coils were filthy, probably just overheated. Cleaned the coils, said everything else looked good. Well, the problem returned almost immediately so I went ahead and replaced the run capacitor and changed the start capacitor/relay - these have a factory hard start kit - with a 5-2-1 kit. The unit started with no problems so I buttoned it up and went about my business. Well, it's 80 degrees in my home again so I'm thinking that the thermal limiter is shot and either that will need to be replaced or bypassed (if there is such a way) or else I'll be in need of a new compressor or more likely a new unit.
Before I invest much more time and money, is there anything you can suggest in terms of things to check?
Here are symptoms:
Condenser fan runs
Compressor starts and eventually stops
Sometimes I can get it to restart, other times it takes quite a long while.
New capacitors (except fan run capacitor) and start relay.
Fan continues to run so avoiding the contactor at this point.