Heater wont shut off

1989 La Sabre heater will not shut off ,,even with engine off
am assuming a relay is stuck/burned out/ but have no idea where offending relay would be located in this car


any help /point to a simple heater wiring diagram for this car would be greatly appreciated

thanx much

Replace your blower control module which is mounted on the heater box above your blower motor.

Thank you very much ,worked like a champ