The standard wiring for Heat/Cool T-stat. Is as follows Red 24 volts to the T-stat. White to the heat. Green to the fan relay. Yellow to the condenser.
green wire is 24 volts from the t-stat to the indoor fan relay, i promise! unless it's a trane. trane has their own wiring codes and i don't remember trane wiring at this time. i can look it up but don't want to. green goes to the indoor fan relay, for real. the fan relay energizes 110 volts and turns the indoor fan on. be careful jacking around with that stuff. remember, you have low voltage from the transformer and t-stat and high voltage everywhere else. the outside stuff is 220 volts. ZZZZZZZZZZZZ!
