I just installed an ecobee 4 and I have a C-wire so it seemed straightforward. The ecobee shows that it detected all the expected wires. However when it tries to call the AC it instantly restarts every time. The heat and the blower work, and the AC worked with the old Honeywell analog thermostat.
I read somewhere that newer equipment can be sensitive to shorts even when older equipment works fine. Could this be the case? How would I diagnose? I just moved into a condo and don't know how to access the control board yet.