My problem is when i turn my blower on it only blows from the lower vents under the radio. it will not blow through the top vents on any setting. i pulled my heater control unit out and looked at things, every thing seems to be switching around and moving like it should, all the lines look okay and the lines under the hood are hooked up correctly. i do not have much experience in this department of the g-body cars so i could use a little help to guide me around with it. any ideas what to search for and what to look at or anyone else experience this problem?