Fan & Defrost/Lower

[peid]

Here's the story, I've had my truck for almost 2 years and never noticed this until last night.

I often thought that when I have the fan on (hot or cold) it doesn't blow properly. Normally I don't complain about blow.........Nevermind.

So we are all on the same page, let me lay out my terminology of the controls.

All the way to the left = CHEST
Next clockwise = CHEST & FEET
Next clockwise = FEET
Next clockwise = FEET & DEFROST
And finally = DEFROST

I was going to town last night and had the controls set to FEET & DEFROST and was talking on the phone and the DEFROST portion was sort of loud so I wanted to switch it just to FEET. Here's the problem.......Nothing changed! It was still blowing out of the FEET & DEFROST.

So, here is my question:

#1 CHEST works as meant
#2 CHEST & FEET, the CHEST part really blows slow, even on high. Most of the air comes out of the FEET
#3 FEET blows exactly the same as FEET & DEFROST, more comes out of the DEFROST than the FEET
#4 FEET & DEFROST, works as meant I believe
#5 DEFROST, works as meant I believe

So I am left with two problems I think, #2 & #3.

Can anybody else test this out and see what they come up with?

[Johnny Law]

I just went out to the driveway and tested this out. You are right. The DEFROST stays on (to a lesser degree) when you have the controls set to FEET only.

Using a highly scientific method (my hand) I switched it back and forth between DEFROST/FEET and just FEET. When you switch it to just FEET the airflow to DEFROST gets diverted to mostly FEET, but not enough for the noise to stop at the highest fan setting. I wonder if the engineers who made it this way figured the windshield may fog up otherwise if there were no airflow?

[03SilverSky]

There is a little known vent under your stearing wheel. Experiment with that vent open and closed and see if it makes a difference.

[peid]

Originally Posted by 03SilverSky

There is a little known vent under your stearing wheel. Experiment with that vent open and closed and see if it makes a difference.

No difference, tried last night!

[dblcabtim]

Originally Posted by peid

No difference, tried last night!

The owners manual (at least in my 04DC manual) shows a picture for each vent position and which vents get air. It's very confusing to me as it appears that most vents get air most of the time regardless of the setting. And it makes several references to closing the "crotch cooler" vent for certain settings to boost performance.

My issue is that the rear vents for the second row passengers do not seem to blow that well. I am going to have the dealer take a look at it. Probably just a design issue.

I'm looking forward to the summer when I can open the sunroof and roll down the rear window and turn off the HVAC all together.

[hndzr8]

Originally Posted by dblcabtim

The owners manual (at least in my 04DC manual) shows a picture for each vent position and which vents get air. It's very confusing to me as it appears that most vents get air most of the time regardless of the setting. And it makes several references to closing the "crotch cooler" vent for certain settings to boost performance.

My issue is that the rear vents for the second row passengers do not seem to blow that well. I am going to have the dealer take a look at it. Probably just a design issue.

I'm looking forward to the summer when I can open the sunroof and roll down the rear window and turn off the HVAC all together.

I looked at my DC manual. There are 3 sized arrows indicating the relative air flow from each vent. On the floor setting the floor (front and rear) gets the most, windsheild moderate and the rear side vents little. On the floor/windsheild setting, the airflow is distrubuted to the floor and windsheild equally (again little to the rear vents). Windsheild only should not have anything out of the floor vents, but some through the lower vent.

It looks like the venting system is working as it is designed, with air through the defroster, on the floor only setting.

In the DC pictures there is only a small amount of air from the pillar vents at any time.

Have a look at your manual and see if it makes sense!

Alan

[mandzach]

bad design is all - no good r+d on this issue. - if you feel the dial as you rotate it you can feel its not a tight click or notch when it turns - its sorta sloppy - wonder if the vents are controled by vacume switchs ? if so we might be able to mod the switch to work better.

[peid]

I could believe this is as designed, but poor to say the least.

Give the operator some credit that they know how to operate a fan.

If I want all the air on my feet, let me!

I also feel the knobs turn sloppy between DEFROST and DEFROST/FEET, not much resistance like there is between others.

I think it is a gimmick, nothing changes, just allows them to say they have a 5 position HVAC system. How about that for marketing?

[jeddclampette]

Well, to add more fuel to the fire, I want to point out something I noticed w/ the two rear vents coming out the bottom rear of the center console. I don't feel anything coming out of them, either in heat or A/C mode. Does anyone else feel anything out of these two bottom vents ?

2003 Tundra LTD

[peid]

Mmmm, I don't think I have those since I have an 02. They did change the center console for 03.

Or are you talking about little opening with slits in them on each corner about 1" X 2"?

I might know what you are talking about.

[SamnJaz]

Originally Posted by jeddclampette

Well, to add more fuel to the fire, I want to point out something I noticed w/ the two rear vents coming out the bottom rear of the center console. I don't feel anything coming out of them, either in heat or A/C mode. Does anyone else feel anything out of these two bottom vents ?

2003 Tundra LTD

Just had to make a quick run..... using peid's definitions this is what I found:

All the way to the left = CHEST - Not alot to the back seat area
Next clockwise = CHEST & FEET - Yes, a good blow.
Next clockwise = FEET - Yes, a good blow.
Next clockwise = FEET & DEFROST - Less then in the FEET mode
And finally = DEFROST - Less then Feet & Defrost

Hope this helps.

[HJSimpson]

I have found that:

FOOT = FOOT + DEFROST as far as air flow goes, both blow on the windshield and down below equally.

The only difference is that FOOT + DEFROST turns on the AC and fresh air (no matter how you have the AC switch, and the recirc switch).

Straight DEFROST puts all the air on the windshield and turns on the AC + fresh air (once again you have no choice with the AC or recirc switch).

I remember some old threads where people were disabling the automatic AC for any DEFROST setting so they could have it on DEFROST + FOOT or DEFROST without the AC coming on. I found just having it on FOOT puts plenty of air on the windshield.

It also seems like during freezing weather any DEFROST setting does not turn on the AC, only during warmer weather.

[Johnny Law]

I tried this in the cruiser, when it is on FEET only, it still blows through the DEFROST too, must be an engineer's thing.

[peid]

When I put my 95 Camry on FEET setting, it ONLY blows on my feet, Zero, Zilch, Not-a, nothing out of the defroster, this is how it should be!