Air flow in heat and a/c questions

Electra

Wishin No More
I am thinking I have some problems with where air comes out and when. I had it looked at at the dealer and it didn't solve any problem.

I have a passenger model, no rear heat system, I do have rear a/c no problems. I do have the timer heater thing, no problems.

Where to start...

The temperature dial - if it isn't on all the way to the last cold square, it is hot as hell. This is without pushing any of the buttons on the right hand dial (a/c, heat, rest). It would seem to me that I should get a variety of temperatures, but maybe it only works with the buttons on the right? I could turn down the a/c temp with the dial no problem this summer. If the heat button is on, it's just all hot, hot. (without any aux heat button on which I only have as the Epbar heater timer thing)

Now the center air flow dial...

If I have it on defrost the window, I get so little air out that I have to manually close all the vents in the front and above the radio to get the window to clear. This does not seem right.

No matter were I turn the air flow dial I get air out of the front vents and above the radio.

And heres the biggest question - the air out of the vents above the radio are ALWAYS ice cold, even if the heat button is on. I was hoping heat would come out of those to help out the back w/ no heat.

I need someone to tell me if this is normal or if I need to take my van back in before I hit the end of my warranty in about 500 miles.

What is normal?
 

talkinghorse43

Well-known member
I am thinking I have some problems with where air comes out and when. I had it looked at at the dealer and it didn't solve any problem.

I have a passenger model, no rear heat system, I do have rear a/c no problems. I do have the timer heater thing, no problems.

Where to start...

The temperature dial - if it isn't on all the way to the last cold square, it is hot as hell. This is without pushing any of the buttons on the right hand dial (a/c, heat, rest). It would seem to me that I should get a variety of temperatures, but maybe it only works with the buttons on the right? I could turn down the a/c temp with the dial no problem this summer. If the heat button is on, it's just all hot, hot. (without any aux heat button on which I only have as the Epbar heater timer thing)

Now the center air flow dial...

If I have it on defrost the window, I get so little air out that I have to manually close all the vents in the front and above the radio to get the window to clear. This does not seem right.

No matter were I turn the air flow dial I get air out of the front vents and above the radio.

And heres the biggest question - the air out of the vents above the radio are ALWAYS ice cold, even if the heat button is on. I was hoping heat would come out of those to help out the back w/ no heat.

I need someone to tell me if this is normal or if I need to take my van back in before I hit the end of my warranty in about 500 miles.

What is normal?
I have an '02, but I think it's the same as yours concerning the heater/A/C. Mine will control temperature on heat, so yours is unusual. Don't understand what you mean "heat button". I don't have such a button, I can only adjust the temperature dial and the unit will then attempt to control temperature using the heater and A/C (if on) as sources of hot or cold air. If I turn the temp dial all the way to the 6 o'clock position (past the click) that turns off the heater and, in winter, gives cold, outside air. Since yours seems to control temp on A/C, seems your heater solenoid (or its control) might be faulty. Might be the solenoid is either always open or always closed, when it should be opening and closing (in pulses) more or less to give more or less heat. On the other hand, since you don't have a rear heater, I guess it could be heating OK if the van's inside temp never makes it to the temp you set. If the van is colder than the temp you set, the heater will try to bring the temp up by heating at max. If that's the case, then the air from the vents will always be hot; unless the dial is in the full 6 o'clock position. The temp sensor it's trying to satisfy is in the dash, so the rear of the van doesn't have to be at the set temp for the heater to throttle down.

My defrost is the same.

The vents above the radio are fresh, unheated air. But, on A/C, they give cooled air. I rarely open them. So, no hope for those in the back from those vents. Won't help you, but I have rear heat and it works great.
 
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BaywoodBill

pre-Yuppiedom
Hi Electra,

It sounds as if something's not right.

As Talkinghorse43 says, the vents on the top are for unheated air but also for a/c air.

The w/s vents, way up there at the bottom of the w/s, ought to really blast out air when the dial is set to the w/s place.

At first I had a hard time figuring out how to get heat on the feet without having hot air blowing in my face. Finally I discovered that turning the dial all the way to have the pointer pointing left would do the job.

I suggest getting the system reviewed under warranty.
 

sikwan

06 Tin Can
I have a 2006, front A/C, front aux heater, rear aftermarket A/C.

The temperature dial - if it isn't on all the way to the last cold square, it is hot as hell. This is without pushing any of the buttons on the right hand dial (a/c, heat, rest). It would seem to me that I should get a variety of temperatures, but maybe it only works with the buttons on the right? I could turn down the a/c temp with the dial no problem this summer. If the heat button is on, it's just all hot, hot. (without any aux heat button on which I only have as the Epbar heater timer thing)
Mine works the same. If I have the aux heater running, it is hot at the 5 o'clock setting. 6 o'clock is cold. With the aux heater off, the heat is a little more controllable.

Do you see the rectangular vent looking thing between the center and right-most circular dials?

There's a little fan underneath that vent that pulls cabin air through a thermistor. That thermistor determines the heat coming out of the vents. When you first set it to 5 o'clock, it will be super hot because the thermistor reading the cabin air temp is cold. Once it starts to read the warm cabin air, the hot air coming out of the vents will start to cool. You just have to be patient.

For me, it irks the heck out of me that I can't get the temp out of the vents the way I want it instantly. It's another mod that I will have to work on. :hmmm:

If I have it on defrost the window, I get so little air out that I have to manually close all the vents in the front and above the radio to get the window to clear. This does not seem right.
Little air is subjective. If you have air coming out, I would suggest turning on your front A/C to help defog your windows.

No matter were I turn the air flow dial I get air out of the front vents and above the radio.
Normal.

And heres the biggest question - the air out of the vents above the radio are ALWAYS ice cold, even if the heat button is on. I was hoping heat would come out of those to help out the back w/ no heat.
Those air vents are always from the outside. There is no heated air coming out of the vents, but I believe the air is air conditioned. I normally have them closed to direct more air to the front vents.
 

Electra

Wishin No More
Hi Electra,


At first I had a hard time figuring out how to get heat on the feet without having hot air blowing in my face. Finally I discovered that turning the dial all the way to have the pointer pointing left would do the job.

I suggest getting the system reviewed under warranty.
I actually have not found any dial setting that does not have air blowing at my face. I took it in to the Freightliner dealer and they did take the dash apart to get at the HVAC system. They said all was fine and it was normal to have air blowing out at the face all the time. Obviously I'm not convienced since I'm here asking you all if this is normal.
 

sailquik

Well-known member
Hi Electra,
Does your Sprinter not have a little control valve wheel on each of the ports
exiting the dash?
They are little black dials with a series of square dots that go from full on to full
off.
If the air blowing in your face annoys you, simply shut the two vents behind the
steering wheel to a lower setting or shut them off completely.
You can also regulate the direction that the air blows from behind the wheel with
the small deflector vanes on each port.
My van has the "top of the dash" vents, and they always blow outside (colder) air.
So, if I don't want the "fresh cold air" in the cabin, I simply shut them off.
Roger
 
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autostaretx

Erratic Member
I actually have not found any dial setting that does not have air blowing at my face.
As Roger/sailquik said, all six of the vents into the cabin (two above radio, two beside the instrument panel, two facing passenger) should be able to be -closed- by spinning their "roller" knobs to the "smallest squares" marking.
The two above the radio are always cold air, so mine stay shut for the winter.
The two on the sides of the instrument panel (and the passenger ones) have center tabs which direct the air up and down, and side to side.
I leave them both closed until i see the engine temperature gauge start to budge, then i open (roll knob to large squares) the one on the right of the panel (closer to heater core, gets warmer sooner). When it is finally putting out perceptibly warm air, i open the door-side one.
I then use the tabs to direct the air at my knuckles or my lap.
I agree that the Sprinter doesn't really toast -my- feet very well, but it does eventually warm up the passenger side.

All of the above is -without- engaging the Aux heater. If i turn that on, the engine temp gets warmer sooner, which means i can open my vents sooner.
The defroster has a -lot- of glass to deal with, and i can barely feel the air flow if i reach forward. On truly frosted/icy mornings, i go out 15 minutes early and fire up the Aux heater (just tap the red button on the timer). 15 minutes later the (not very thick) windshield ice is ready to be easily squeegied off.

I think i have more a "tunable" temperature knob (leftmost circular knob) than you're reporting. I can bring it up to 4 o'clock before warmth becomes obvious, and then it's controllable up from there. 2 to 3 o'clock gives adequate heat for long drives near freezing, 12 o'clock is hot.

stay warm
--dick
 

Pascal

New member
I think I have a problem with my temperature control knob. If i put it to 6 o'clock it is cold but if i move it to the first next blue square , it is very very hot.
How does the temp control knob works?? And what does it control (sensor, rheostat , cable)
:thinking:
 

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