4 hi 4lo auto4 heater

my problem is when i push any of the above buttons the truck will shift like it is suppose to but the light beside the button continues to blink and never stops but i do no the truck is shifting because 4lo is easy to tell and 4hi i can fill when i drive plus you can here the shifting takeing place also my switch that contols the heater as far as heater and vent or defroster air will only blow out the vents you can turn the knob but it does not change where the air blows out all fuses are good inside truck and under hood fan blower works fine and other things seem to be ok are these to possiably related or what could be the cause?the truck runs fine 56000 miles on truck 2dr auto

Most of the heater directional controls are vacuum driven. Look for cracked or disconnected lines under the dash and in the engine compartment. Also in my wifes 95 Grand Am we found that the knob was actually just turning and the directional control was never moving.