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Ok, I need help with this one. I have a 2006 Chevy Cobalt which I thought the blower motor was out because when it started to get cold this winter I could feel the heat but it wasn't blowing as it should. I changed the blower motor and blower resistor only to find out that the original blower wasn't bad and actually blew better than the newly purchased blower. However, the blower would only blow when on the cool temperature setting and would weaken when i switch to a hotter setting. Now i'm not sure if there's a diverter that's not diverting properly or if there's a blockage in the heater core at some point... HELP IT'S COLD IN TEXAS!  

there are blend doors . that control the cool or warm air...




008 22724333 CAM. Air Distributor  CAM,MODE CONT (INCLS ACTUATOR). Required: 01 For: A (2005-2010) (2005 - 2010). For: A (2007-2010) (2007 - 2010). $42.55

010 10393075 ACTUATOR. A/C Control.  ACTUATOR,TEMP VLV (ACDelco #15-73108). Required: 01For: A ELEC HTR(C40),A/C FRT ELEC CONT(C67) (2005-2010) (2005 - 2010). For: A ELEC HTR(C40),A/C FRT ... $65.40

037 15842338 ACTUATOR. A/C Control.  ACTUATOR,AIR INL VLV(ACDelco #15-73513). Required: 01For: A A/C FRT ELEC CONT(C67) (2005-2010) (2005 - 2010). For: A A/C FRT ELEC CONT(C67) (2007-2010... $62.72

there might be two different designs.. so be sure to look up the parts with a vin number or by looking to see  the C codes on the RPO sheet in the car some place.. where there will be dozens of 3 digit codes in rows and columns..

the actuators move the doors to control the airflow..   the actuators can fail...   since i do drivability i have not had one of these in my hand..  or taken one apart.. they can fail to function properly.. they are known to fail..  there are also problems with the air doors on some cars that bind.. and require more torque to move than the actuators can provide..  

usually removing the actuators and seeing if the air door moves somewhere between 30 to 90 degrees... freely..  you should be able to tell when it reaches each end..


a  question.. can you verify the engine coolant level????     i know its on the back side of the motor..  can you reach the heater hoses and see if they are getting hot...  low coolant levels will cause air bubbles to be in the heater cores.. air does not have the heat to loose to the airflow..

blown head gaskets can also let combustion air into the cooling system since air is lighter than coolant. . it stays high in the motor and pushes the coolant down .. many times away from the cylinder head and the heater core..

verify that with the engine running. that when you switch the knobs.. from off to cool to warm.. to defrost.. the actuators actually divert the airflow..

you might be able to see them move the actuator also..  perhaps a scrap of tape or a paint mark on the end of the shaft to see how far is moves..  

you will have to open the image above in a new window.. its larger than you can see..  or print it out for under the dash idea of where stuff is..

need more info.. just post.. i will usually be around..  

Okay I found the actuator that moves when the temperature is selected. It seems to rotate about a quarter turn. Any idea how far these are supposed to rotate? I removed the actuator and turned the diverter by hand it was kinda hard. Airflow still seemed very restricted. Any ideas? Coolant level was okay as well.  

there are 3 actuators... #8, #10, #28 and a Cabin air filter more than likely... perhaps your cabin air filter is clogged..

#033   52493319 FILTER. Air Distributor FILTER, PASS COMPT AIR(ACDelco #CF125).


a  quarter turn looks about right...  but i am not familiar with it..

what happens with the others when you work the controls..


does it divert from fresh air to recycled air..

does it divert from foot air.. to face air.. to defrost..

and does the temp change for each?????

this is what i mean for testing the system....

identifying which section is not working..

changing the cabin air filter might be covered in your owners manual.. if you don't have the info.. post.. i might be able to find it..  

Well the problem seems to be when the temp. is only selected to warm. All settings (face, floor and defrost) seem to be restricted in the same manor. when the temperature is selected to warm and the mode actuator is selected to face (or any mode for that matter) and you turn it to cold it actually SLOWS down the airflow. Doesn't that mean it's the actuator (which seems to be working properly)?  

is the cabin air  FILTER CLOGGED??????

i am slightly confused by your last post...

there is on most of these systems an actuator that selects from IN CAR recycled air.. to Fresh air through the vents usually in front of the windshield..  i don't know where the cobalt gets the fresh air inlet from.... it looks like the door #29 actuated by  item 28 both of which are directly under marker #1..

the image is looking THROUGH the firewall..  this is the engine side.. view as if the firewall was NOT there..

under dash insulation or debris could have gotten pulled in or over the interior opening..  or debris blocking the forward fresh air vent..  

i have found other cars that had all kind of debris over the faces of the heater core and the evaporator..   more than a few caused by mice building homes and dragging stuff in...   took one customer a few days to trap a lizard that would come out and sun on the dash of her saturn.. only to hide when anybody came near.. she caught him with a trap i designed after a few days..  a strawberry in the bottom of a clear plastic cup layed on its side.. for several days..  fresh fruit added daily..  eventually.. the cup was positioned between the console and the seat.. in a normal bottom down direction..  the lizard went in.. and could not get out..    she actually drove the lizard over 100 miles back to her parents house to set him free..  

one more thing... is the FAN speed staying constant.. not really changing speed on its own....  

Dang, i thought gecko's were supposed to save money on car insurnace not cause HVAC mayhem?! Anyways, the cabin filter isn't clogged, the fan speed is constant.  

blockage in the airflow...   find flapper at indicator 1..    you might be able to see the back side where it gets air from the inside of the car..  grommet 27 is flat against the inside top of the firewall where you cannot see it.. but it should open in the back side for recirculated air..

could the fan blade be the wrong shape???     the squirrel cage blower wheels do not work as well in the reverse rotation..

could it be loose on the shaft???  

Okay the problem was fixed. when the temperature is selected to warm the mode actuator turns the adapter between 7 & 8 just a little bit farther to open the flap. Said adapter was loose and wasn't engaging some of the #7's and was getting hung up. What a pain in the lizard to access this stuff! Thanks for all your help! appreciate it.  

glad to have helped...