I have a Trane Central A/C & Heat Unit. My Unit just started continually running, Won't cycle on & off. I can adjust the temp and it shuts off fine. Also comes on perfectly. Heats & Cools Fine. But won't cycle back off automatically afterwards! Replaced the thermostat and it still does the same thing. Please Help. I am hoping to avoid another High electric Bill and A more costly Air Conditioner repair.. Thank You