Honda Acura NSX 1991 Service Manual page 917

From page 22-28
Check for continuity between the
wire(s) and body ground.
Test the air mix control motor at
the heater (page 22-90).
Y E S
Substitute a known-good control
unit and recheck. If symptomlin-
or BLKlGRN wire(s) between the
air mix control motor and control
Replace the air mix control motor.