Good Heat....cold Feet ??

My Heater Controlls Are As Confused As I Am. My Ac And Heater Work Great, But The Problem Is When The Dash Selector Is Set To Any Floor Setting The Air Blows Out The Defrost Or The Dash, Depending On The Floor Setting Selected, But Nothing On The Floor. Hope That Made Sense ?? I Am Guessing It Is The Motor / Drive That Moves The Door To The Selected Setting That Is Not Working Right. I Have A 99 Blazer 4wd. How Hard Is It To Get To This Mechanism ?? I Am Old And Brittle And Laying On The Floor To Reach Under The Dash Is Getting Harder All The Time !!! Also Is The Assembly Centered Under The Dash Or More On The Passenger Side ?? Any Help / Guidence For An Old Grey Haired Fart Will Be Appreciated.
Thanks
Ron

My Heater Controlls Are As Confused As I Am. My Ac And Heater Work Great, But The Problem Is When The Dash Selector Is Set To Any Floor Setting The Air Blows Out The Defrost Or The Dash, Depending On The Floor Setting Selected, But Nothing On The Floor. Hope That Made Sense ?? I Am Guessing It Is The Motor / Drive That Moves The Door To The Selected Setting That Is Not Working Right. I Have A 99 Blazer 4wd. How Hard Is It To Get To This Mechanism ?? I Am Old And Brittle And Laying On The Floor To Reach Under The Dash Is Getting Harder All The Time !!! Also Is The Assembly Centered Under The Dash Or More On The Passenger Side ?? Any Help / Guidence For An Old Grey Haired Fart Will Be Appreciated.
Thanks
Ron


Auto or manual AC/heater controls?

First thing is to check for good vacuum from engine to heater controls.
Check for vacuum on the vacuum ball and for bad or cracked or unplugged vacuum lines rubber and plastic.

I do not think the blend dfoor mortor is the problem but look up in the how to section for information on it.

Look under the hood for the vacuum ball or canister. $10 bucks says a vacuum line popped off.

Thanks For The Help Guys !!!!! I Will Try To Find The Vacume Canister As Suggested And Hope For A Simple Vacume Hose Fix. I Am Getting To Old To Crawl Around On The Floorboards Of Vehicles Any More. I Hurt For Days After !!!! I Will Report Back On What I Find.
Thanks
Ron

ALSO IT IS A MANUAL SELECTOR / CONTROL FOR THE DIFFERENT SETTINGS

well here is where i am at, i have the dash taken apart and have located 3 different vacuum operated valves. each has different functions for door placement / air direction. each one is working. i don't know if there working properly or not, but they are working. are there more than three of these ?? i also have taken the control / selector knob apart and cleaned it and re installed it. made no difference. i have removed the air lines to each of the valves and moved them by hand to try to find the floor setting and got no where with that. i am now wondering if the door has came loose inside of the duct work and will not move due to that. also i did find a vacuum line under the hood, on drivers side Near the firewall that was shot / leaking. i replaced it with some thin walled tubing i had on hand, [will replace it with proper line when part stores open]. the line i have on now is collapsing when car is running due to the vacuum. i am thinking it has no effect on the heater controls since they have vacuum to them. what do you think i might try next ?? this turd is getting the best of me right now !!
ron

well here is where i am at, i have the dash taken apart and have located 3 different vacuum operated valves. each has different functions for door placement / air direction. each one is working. i don't know if there working properly or not, but they are working. are there more than three of these ?? i also have taken the control / selector knob apart and cleaned it and re installed it. made no difference. i have removed the air lines to each of the valves and moved them by hand to try to find the floor setting and got no where with that. i am now wondering if the door has came loose inside of the duct work and will not move due to that. also i did find a vacuum line under the hood, on drivers side Near the firewall that was shot / leaking. i replaced it with some thin walled tubing i had on hand, [will replace it with proper line when part stores open]. the line i have on now is collapsing when car is running due to the vacuum. i am thinking it has no effect on the heater controls since they have vacuum to them. what do you think i might try next ?? this turd is getting the best of me right now !!
ron


The heater controls have to have good engine vacuum for them to work right.
If vacuum lines are bad fix them.
Srtart at enguine and work all of the way to vacuum ball and and onto heater controls.
Good Luck
Get a good vacuum gauge and check vacuum readings.

thanks for the reply !! i have spent the last 18 hours working on this thing and all i have accomplished is fixing one vacuum line that was bad and breaking the emergency brake release cable !! LOL!!! i have had the dash removed so i could get a good visual and do a non educated check of the operating components of the heating blower system. all parts are working to some extent. i also removed the module thingy that moves the door from heat to cool. that is in good working order as well. i have looked all over the top side of the engine compartment and cannot for the life of me find the vacuum ball that has been mentioned to be checked. can some one point me in the direction where that thing is hid. i know what they are, and look like, and am wondering if on this vehicle it might be located on the bottom side of engine compartment or tucked away in a fender some where. one last thing, it looks like i need to invest in a service manual, what is the best one to get ?? i know there are some out there that are real limited on information given.
thanks
ron

http://www.alldata.com/products/diy/index.html

The vacuum ball may be in the right front fender area.
Follow the vacuum lines from engine to it and threw it to heater controls.

Is the heater control getting good engine vacuum?

like mt sez are you gettin good vacuem...key thing here is n engine creates stronger vacuem at idle speeds,,higher speed cause lose of vacuem..ive had simialr cheeyut n try find it n check when idle n were fine..but as got her wound up (say 55) the vent would flop to defrost..it ended up beyun one of the 3 under dash (werked at idle but at low vac. shed wouldnt hold..this was a 95 gmc safari..and cant tell whick one was which..vacuem gauge will tell ya