My fan won't come on .I changed the thermostat.It would not come on at first .I let it sit in the on position for 20 minutes it finally came on.It would not cut off.So I cut it off to rest it.The fan will not come back on.

Could be a bad fan relay or a bad fan motor capacitor or fan motor, also check for loose wire connections.

Re-check your wiring.

XenoSapien