heat/air stuck on vents only (no feet or defrost)
#1
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heat/air stuck on vents only (no feet or defrost)
as the title says my air and heat will only blow out of the vents.. when i press the buttons from defrost and feet they light up as though they have changed but still air only comes from the vents- no warm feet and no defrosted windshield.. im assuming its a motor failure that changes the flow of air.. could it be something else? where should i start trouble shooting? thanks for any help!... btw its a 98 4dr accord 4cyl model.
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#2
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Re: heat/air stuck on vents only (no feet or defrost)
When you press the buttons to change ventilation mode can you hear the humming of the mode control motor inside the heater unit? If you cannot hear the motor spin then there's a problem with the motor or the cabling. Do the test with engine not running and ventilator speed low.
#3
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Re: heat/air stuck on vents only (no feet or defrost)
tried that and i had the fan on the lowest setting and when i change the modes from lets say vent to floorboard there is no change in noise- just the small "hum" of the fan blowing
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Re: heat/air stuck on vents only (no feet or defrost)
Must be the mode control motor is not working (like you suggested in your first post). There's a good chance you can locate it under the dashboard on the driver's side, to the right of the throttle pedal. It has a seven wire connector attached to it.
#5
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Re: heat/air stuck on vents only (no feet or defrost)
appreciate the info, i was very worried i was going to have to dig and dig to find it somewhere deep in the dash.
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#6
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Re: heat/air stuck on vents only (no feet or defrost)
another question.. when i search ebay for this part it is separate from the blower motor correct? so what exactly is it called and what should i search for?
#7
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Re: heat/air stuck on vents only (no feet or defrost)
nevermind, apparently it is called exactly what you said it was.. a "mode motor". thanks again
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Re: heat/air stuck on vents only (no feet or defrost)
I remember spending half a day taking out the center console, radio, instrument panel etc... only to find out that the ventilation control cable had come off because some day my foot had slipped off the throttle pedal... (car had manual ventilation controls)
#10
Re: heat/air stuck on vents only (no feet or defrost)
I think it's usually the motor underneath. I had this last year and swapped in a good one and all fixed. I believe the right word on the Accords is it's called a blend door actuator.
https://www.autozone.com/cooling-hea...B&gclsrc=aw.ds
You can check to see if this is it by looking. It's on the drivers side, right next to the space behind the dash. Just have someone push any buttong while on and see if it moves. It probably won't. If it does, then it got disconnected, but more likely it is dead.
Watch this for the location.
https://www.autozone.com/cooling-hea...B&gclsrc=aw.ds
You can check to see if this is it by looking. It's on the drivers side, right next to the space behind the dash. Just have someone push any buttong while on and see if it moves. It probably won't. If it does, then it got disconnected, but more likely it is dead.
Watch this for the location.
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#12
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Re: heat/air stuck on vents only (no feet or defrost)
98-02 all gen 6
it worked guys, my mode motor was just a little weak and it didn't help I hardly ever have to use defrost and rarely change modes, so when I didn't drive it for a month or probably longer it got stuck on defrost when i used it one morning.
I could see it moving and helped it the rest of the way with my finger, hit the joints with some silicone spray and so far - so good.
it worked guys, my mode motor was just a little weak and it didn't help I hardly ever have to use defrost and rarely change modes, so when I didn't drive it for a month or probably longer it got stuck on defrost when i used it one morning.
I could see it moving and helped it the rest of the way with my finger, hit the joints with some silicone spray and so far - so good.
#13
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Re: heat/air stuck on vents only (no feet or defrost)
Great - lubrication seemed to fix it. I've heard you should occasionally run the air conditioning during the winter just to lubricate/move the compressor and other components. Maybe the same applies to the blend door actuator. So occasionally selecting defrost on these older cars whether you need it or not is probably a good idea.
#14
Re: heat/air stuck on vents only (no feet or defrost)
After driving in the first cold rain of the season, I had the same issue.
It just would not change into DEFROST or DEFROST+FLOOR vents, only FRONT and/or FLOOR vents.
Took pics of EVERYTHING, then removed the MODE CONTROL MOTOR (2 screws) and tried the various 6 modes to see if the motor was sticking, it was not.
But what I did find is it was reluctant to move towards the DEFROST or DEFROST+FLOOR modes.
What I found out it was the buttons themselves that were not always making good electrical contact.
If you pressed, released, then Pressed+HOLD the defrost button for 6 seconds, it would move the motor to the correct position fully without hesitation.
Since I had the motor removed, I sprayed some silicon lube on all the mechanical linkage just because, figured it couldn't hurt too much on a 25yo car.
I sprayed some LPS #03116 cfc-free electro contact cleaner between the buttons WITHOUT removing the control module and that seemed to make better electrical contact now.
I mention that specific contact cleaner because it is VERY fast drying/evaporating (20 seconds) and more importantly did not melt any plastic parts like some contact cleaners can.
I suppose you could use DENATURED ALCOHOL too, as it will NOT melt plastics, but not as effective and takes about 6 minutes to dry.
Hope this might help save someone some time/grief/asprin/tequlia.
It just would not change into DEFROST or DEFROST+FLOOR vents, only FRONT and/or FLOOR vents.
Took pics of EVERYTHING, then removed the MODE CONTROL MOTOR (2 screws) and tried the various 6 modes to see if the motor was sticking, it was not.
But what I did find is it was reluctant to move towards the DEFROST or DEFROST+FLOOR modes.
What I found out it was the buttons themselves that were not always making good electrical contact.
If you pressed, released, then Pressed+HOLD the defrost button for 6 seconds, it would move the motor to the correct position fully without hesitation.
Since I had the motor removed, I sprayed some silicon lube on all the mechanical linkage just because, figured it couldn't hurt too much on a 25yo car.
I sprayed some LPS #03116 cfc-free electro contact cleaner between the buttons WITHOUT removing the control module and that seemed to make better electrical contact now.
I mention that specific contact cleaner because it is VERY fast drying/evaporating (20 seconds) and more importantly did not melt any plastic parts like some contact cleaners can.
I suppose you could use DENATURED ALCOHOL too, as it will NOT melt plastics, but not as effective and takes about 6 minutes to dry.
Hope this might help save someone some time/grief/asprin/tequlia.
Last edited by jymm; 01-31-2022 at 09:24 AM. Reason: typo
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