The most likely reason that the heater control won't change the air flow is that the cable that moves the diverter valve has broken and will need to be replaced.
The heater core in a 1987 Chevy Celebrity is in the heater plenum to the right of the hump and below the glove compartment.
Which engine does your car have?
Are you asking about the heater blower motor or the engine cooling blower motor?
You can replace the ignition control module and the crankshaft position sensor as required.
how do i change a heater core on a 2000 Chevy impalla
Where is the heater control valve for a 93 Chevy van, G-20, 5.O
The heater blower motor is under the hood bolted to the heater plenum on the passenger side of the car.
"Where is the heater controll valve on a 2001 Chevy S-10 controll Valve? "
Does your 1986 Chevy Celebrity have the 2.5L 4 cylinder engine or the 2.8L V6?
There is a fuse for the blower motor on the fuse panel, I do not know of a relay.
On a 1989 Chevy Celebrity the timing is controlled by the engine control module, there is no specification or provision for adjusting the timing manually.
where is the heater control valve on a 1994 2500 suburban