I turn on heater and it sounds plugged when on front defrost? When I turn it to the feet it seems to work fine. Does not defrost front window while set that way. Where can I look. It is a 2009 Saturn Aura.

what are you defrosting>> it's 100f here, we need non
are you Down under in winter> no location told.
there are 2 things with that name on cars
HVAC heater in defrost mode uses AC to do that.
and
rear window glass heater defroster < (i will skip that)
check fuses first
make sure AC compressor the engine spins pulley and front at idle.
scan the PCM for errors. DTC
get a shop to take a look, YES !

On most vehicles today ,there is a electric motor that works the vents .
sounds like it might need to be replaced.
it is usually under the dash....bolted to the heater box.

hope this helps.

This may be due to a bad heater core or dirty core with a plugged water drain, first see if the a/c works. turn it on and see if the air gets cold and if the ac compressor works.

The way the defrost works to keep windows from fogging up is that when the front defroster is tuned on the ac should also be on, on most cars when you go to defrost it will turn ac on automatic. the system then uses hot and cold air to remove the moisture in the air to avoid window fogging. if your a/c is not working then that may cause window to fog, but if you are also getting a smell then the drain that lets out condensation may be plugged and then water builds up and also mold from always being wet and when heat is on you smell that.


i want you to run the defrost and when windows fog up wipe window with hand and see if it is greasy . if it feels oily then you may have a bad heater core, the core leaks coolant out and steam and causing windows to fog up with a flim of grease.

make him do it again... ?

They had problems with the heater switch loosening up. Sometimes it can be fixed sometimes the whole heater assy has to be replaced. The heater knob will pull off. Pull that off and then there is a nut that should be loose. Tighten that nut but be careful not to over tighten because you break this piece and you will be buying the heater assy. After you tighten that reinstall know and see if that fixes it.

you have a bad control switch.

Hi: On the back of the heater control unit are vacuum lines, make sure plug is firmly attached. FIRST though check if vehicle does not go into 4WD high. If not then you probably have a vacuum problem under the hood as vacuum controls heater, 4WD and other functions. Check to make sure vacuum lines under the hood are all attached starting with the vacuum pod (located in front L fender by brake module.) and chasing them under the hood. If you have vacuum then check heater control module and lastly heater door vacuum actuators. Hope this helps.

heater box is warped doors not closing fully

See this post:

http://www.fixya.com/cars/t1142051-hvac_control_head_mode_dial

The vent actuators are vacuum controlled on this model. Do you hear a hissing sound when you turn the control knob? If not, then you'll need to check the pipe or hose connections. Start with the vacuum reservoir bottle on the right hand wing just in front of the door. Ther'll be a hose from the inlet manifold to the bottle, make sure that's connected & air tight. The other pipe from the bottle goes to the heater controls. Has the radio been removed or any work done in that area? If all appears fine, remove the radio & make sure the large white, multi-hosed connector is fitted securely to the control switch & all the pipes are connected to it.
Good luck, let me know if you need any further help.