The air is cold every thing works good but in auto position the blower will not shut off.Its like I have the unit on run but its on auto.Anyone have info on this problem?

This problem is common, but it can have various solutions among them are fan limit control, blower relay, thermostat, control board and thermostat wiring.

The most common cause is that the contacts on the blower relay welds shut. Disconnecting the "G" terminal at the furnace, eliminates the wiring and thermostat.