Heater and AC only blows through the defrost and floor vents. on 2003 Mercury Grand Marquis

The control button only reads floor and vent. Floor vent on driver side seems blocked, not much air.

by in Johnstown, PA on July 23, 2012
3 answers
ANSWER by , July 24, 2012
you may have a blend door issue seek a diag and est
ANSWER by , July 24, 2012
you need to check your vacuum lines under the dash
ANSWER by , July 29, 2012
Poss. MODE control motor.