2006 heater control problem

ive got a 2006 v6 3800 malibu LT.
the heat only comes out the defrost.when i adjust to any other vent it stays on defrost. i cant adjust the heat temp either,turn it to cool and it stays hot. the recirulation light dosnt come on when pushed nor the other button,i forget what is.
basicly i have no control over the heat. this is a used car and it came like that.i checked all the fuses.
seen as this is a new car i would like a idea as to what it could be before i start tearing it apart. your help is greatly appreciated. thank you.
it wasnt bought from a dealership.

The heater in '04 - '07 Malibus and Maxxes are trouble-prone. Check archives in this forum and also in Edmund's forum archives, because it's been discussed at length. I forget what the issue and fix is (it's not a simple thing, as I recall). Until this past May, I was living in Florida and ignored the issues, but now as I'm in NC, I notice that my engine bay makes awful-sounding noises when my heat is on in my '04 Maxx. But, my heat works fine at the moment (just sounds like it's going to die).

ill give that forum a look. ive been searching,but nothing seems relevant to my situation.
thanks for the reply.

To hear if the motors are running for the vent doors, turn ignition on but don't start engine. Turn fan off and rotate heat control from cold to hot. You should be able to hear the motor running to its new position. I've had to replace the pulse count motor on my 04 Malibu.

The pulse count motor is what I was remembering....

I'm not 100% sure if it's the same thing on Malibu, but on Windstar the climate selectory output is controlled with the engine vacuum. It's called a "vaccum controlled selector system."

Defrost is the default position, with no vaccum.
When you select vent for example, it apply vacuum on system.

The vacuum for this control comes from the back of the upper intake manifold, to a vacuum reservoir box that is on the inner fender, on the passenger side.

This box holds some vacuum to hold the controls in place while the engine is off. From the reservoir box, a vacuum line passes through the firewall into the passenger compartment to provide the control and drive to the diverted system.

So you must have a vacuum leak. I'm not sure if reservoir and other components are located on same place that mine.

If you want more info, search in the Windstar forum, and search for "defrost only".


For the temp selector problem, it's another problem. It may be a faulty blend door actuator.

For the recirculating, it should be related to the air vacuum leak.

I'm not 100% sure if it's the same thing on Malibu, but on Windstar the climate selectory output is controlled with the engine vacuum. It's called a "vaccum controlled selector system."

Defrost is the default position, with no vaccum.
When you select vent for example, it apply vacuum on system.

The vacuum for this control comes from the back of the upper intake manifold, to a vacuum reservoir box that is on the inner fender, on the passenger side.

This box holds some vacuum to hold the controls in place while the engine is off. From the reservoir box, a vacuum line passes through the firewall into the passenger compartment to provide the control and drive to the diverted system.

So you must have a vacuum leak. I'm not sure if reservoir and other components are located on same place that mine.

If you want more info, search in the Windstar forum, and search for "defrost only".


For the temp selector problem, it's another problem. It may be a faulty blend door actuator.

For the recirculating, it should be related to the air vacuum leak.

not on the newer chevies, they are 100% electrically controlled, blend doors and vent selection doors.

I've posted this link before.

https://delphi.com/shared/pdf/ppd/heatcool/hvac_controls.pdf

It's the system the newer cars use.

I suggest you to buy the book "Automotive Heating & Air Conditioning" from Haynes to diagnose and repair your problem. The book number is 10425. Get the last version.

Also get the service manual for your car.

I don't think it's a problem with electric motors cause all of them doesn't work. It may be a broken wire connection behind the HVAC panel. You may have to remove it.

You can also diagnose which portion of the circuit is not working by removing HVAC fuses one by one, and connect an ampere-meter on fuse's connection. Turn key to ON. If you don't have current, then the open connection is in THIS circuit. Test to see if meter works before testing.

pulled the passenger side fender off and ther waas a cover that was off and sitting inside thethe hole it was covering.i could feel air miving inside it so closed it back off. still the heater is only on in defrost.does anyone have the schematics to the vacuum system,i got a haynes and a chiltons book from the library but neither have anything on the vacuum of the car.

Once again, as pointed out before, your model does not use vacuum for the climate control. It is controlled by an electronic control panel which drives electric motors which in turn adjust the position of the doors in the vents.

I suggest you take it to a dealer for diagnosis.

oh,my bad.
so there is no resivoir. i did turn the knobs on the heater control and i heard no motors kicking in.so basicly ,somewhere in the controls is where my problem is.the person who had owned it before me had got into a frontend collision and spilled some drink all around where the radio and other controls are.
ill bust out the trusty voltmeter.:icon16:

It's no good using a meter without having a wiring diagram and knowing how the circuit works. The only thing you can do is check all fuses and see if there are any broken wires. I think you'll save yourself a lot of time and trouble if you take it to a dealer. You'll most probably have to buy a new part anyway. In checking to hear if the motors run, have ignition on, engine and fan off. This is to kill background noise so that you can hear the motors. Turn heat control from max to min and then back again. You should hear the whine of the motors.