My heater up front blows cold. the heat in back works great.what is wrong on 2000 Chevrolet Tahoe

Ive replaced the actuator under the dash and both in cab air filters what else could be wrong

by in Canehill, AR on April 11, 2014
1 answer
ANSWER by , February 23, 2015
I did not do anything as yet,cant find temperature door actuator or location cabin filters. this is 2000 chevy tahoe 5.3.