I have a Bryant heat pump and the blower continues to run about 10 to 15 minutes after the heat coils shut off. The air gets really
Cold before blower shuts off. Anyone out there that can give me some advise?

Many heat systems have a thermal switch, (Limit Switch) which allows the fan to continue until the coils are brought to a lower temperature. Without the fan, the temperature could rise and cause heat damage to related componants. I have experienced these "limit switches" malfunctioning and getting stuck, allowing the fan to run continuously while the heating elements cycle on and off, again and again. I'm not a tech by far, but that's what I can share.