No Dash or floor vent!!!

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Jan 23, 2007 | 12:10 AM

UcaN

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Joined: Oct 2006

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From: south cali

No Dash or floor vent!!!

Hi everyone

Anybody know what switch or servo goes bad, or what is commonly broken, when none of the vent positions work......all air is vented to defrost, weather max a/c is on or heat. Moving the vent location switch to floor, or dash does nothing.

Truck is a 2000 super duty, 7.3 powerstroke.

thanks

Jan 24, 2007 | 06:25 AM

ubereal2

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Joined: Dec 2006

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From: Lexington Mo

I'd think this would either be a bad switch, or most likely a bad actuator, wich is an electric motor that opens and closes the flaps/doors. that one I think is located towards the floorboard, on near the center of the dash. If you can find it have the truck running, and adjust the control and see if the motor works.
That's a common thing. If it isn't working it could be a switch though. Actuator is more common.
Bob

Jan 24, 2007 | 07:33 AM

tjc transport

i ain't rite

Joined: Mar 2005

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From: Marlboro Mental Hospital.

not sure about the newer trucks, but the older trucks were vacuum opperated, and defroster was the default setting when the vacuum line to the switch got broke.

Jan 24, 2007 | 08:30 AM

projectSHO89

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Joined: Jan 2004

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From: St Louis

Quote:

Originally Posted by tjc transport

not sure about the newer trucks, but the older trucks were vacuum opperated, and defroster was the default setting when the vacuum line to the switch got broke.

The new ones are all still vacuum operated and defrost is still the default position (safety/visibility) when vacuum is lost.

Most common failure is a broken, split, or otherwise damaged vacuum line or connection located between the battery and the firewall. Check there first.

Steve

Jan 25, 2007 | 12:15 PM

UcaN

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From: south cali

vent

Thanks guys..

I'll look into that......i just purchased the truck not that long ago and i am barely getting familiar with it.

Feb 23, 2007 | 04:03 PM

dayooper13

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Joined: Feb 2007

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Quote:

Originally Posted by projectSHO89

...Most common failure is a broken, split, or otherwise damaged vacuum line or connection located between the battery and the firewall. Check there first.

Steve

First off, I am glad that someone else is having this problem too. I just got this truck ('98 Ford Ranger) and am not able to get the vents to work. My question is, how do I know which Lines are Vacuum lines and how do I know if that is the problem??? At first I thought it was the "Blend Door" and I almost did the hole drilling thing mentioned in another thread, but then I realized that that was just for only getting hot air or cold, I can freely switch between the two, I just can't get it to come out of the floor or upper vents only the defrosters. Any help is appreciated. -Da Yooper-

P.S. If it is the lines is this an easy fix (replacing the lines) or a more difficult one? -Thanks-

Feb 23, 2007 | 04:16 PM

tjc transport

i ain't rite

Joined: Mar 2005

Posts: 65,507

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From: Marlboro Mental Hospital.

again, i am not to familiar with the newer trucks, but with the pre 97 rigs, 99% of the time it is a broken vacuum line at the vacuum "T" or manifold that is bolted to the upper firewall in the engine bay, in the area of the passenger side valve cover, just below the hood weatherstripping. look for a very small, like 1/16 inch black vacuum line that goes towards the ac/heater box. that is the one that always breaks. it is such a small line that you won't even get a miss from the vacuum release.

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Mar 13, 2007 | 05:35 PM

AStevens

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Joined: Mar 2007

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03 F250 7.3

I just had the defrost only problem with my dad's truck.

To start, I checked the vacuum lines under the "heat shield" looking thing and found that they were all tight. The plastic gray vacuum tube running over to the evap valve? (sits above right side valve cover) had been pulled/knocked loose. This had caused the vacuum pump to run constantly for a while.

My father, who is mostly deaf, "had heard somethin' runnin' up under there". I pulled the line from the vacuum cannister and used a hand vacuum pump to pull 5" on the line going to the a/c vents - the air started coming from the vents as advertised and the needle on the hand pump didn't drop, so there was no leak in the line going to the distribution panel near the switch.

I then pulled the elec plug on the pump and it was getting 12vdc. Bad pump. Parts place here in Tucson stocks the belt driven pumps, but not the electrical ones after '99. $195+tax at the dealer and the a/c is working as advertised.

Those plastic vacuum tubes in an area with that much heat are a problem waiting to happen. I'll advise dad to get some vacuum line and carry it in the truck with him as insurance.