Where is the heater control valve on a 1989 Buick electra Park Avenue 3.8 engine located?

The heater control valve on a 1989 Buick Electra Park Avenue with a 3.8 engine is typically located near the firewall on the passenger side of the engine bay. It is connected to the heater hoses that run from the engine to the heater core. The valve itself may be mounted on the engine or on the firewall and is usually accessible from the top of the engine compartment.