Chevrolet Repair: 1998 chevy blazer floor vent not functioning, chevy blazer, lititz pa

Question
Hello Mark:

thank you for offering your help on allexperts.com!
we recently notice that the floor heat vent is not blowing any air.  when the control is set to "heater" (floor), heat blows from windsheild defrost vents only.  all other vent controls work.
the only work done on the vehicle recently was front end work: replace idler arm, lower/upper ball joints, tierod end, and wheel bearing housing.  Any advice would be welcomed and appreciated.

Debbie and John Mengoni
w/ cold feet in Lititz, PA!  

Answer
Hi Debbie, There are a couple of things to check/or that could be the problem. First I want you to check the vacuum line that goes to the heater door. This is next to the gas pedal and i think it has 2 lines going to it. Be sure that you didn't kick the hose off it with your foot. This would be the easiest repair of ALL. The next could be a bad heater control head. It the heater control head has oil in the the lines going to it, you also need to replace the transfer case vacuum switch. I stop here, if you need more help let me know.

Have a Great New Year

Mark