Fan blower stuck in defrost. 1999 E350 ford van.

Discussion in 'Domestics' started by BC, Sep 28, 2017.

  1. BC

    BC Full Member

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    Please fill out the following to ask a question.

    MAKE:Ford
    MODEL: E.350
    YEAR:1999
    MILES:80,000
    ENGINE:7.3 diesel
    DESCRIBE ISSUE....
    A/C is blowing out the defrost vent only when is any position. If its a vacuum hose where is the best place to look. Or could this be the selector switch?

    Thank you.
     
  2. kev2

    kev2 wrench

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    there are other videos there to help with this....
     
  3. BC

    BC Full Member

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    This was a great help for sure. I follow this and see what I find and post results.

    Thank you.
     
  4. jd

    jd Hero Member

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    Where does the 7.3 get its Vacuum to do things like control vents?
    Let me set this up. The A/C and Heat (sometimes called HVAC for HeatVentAirCondition) use vacuum with a check valve and reserve tank, at least with gas engines. Vacuum alone will work the system, but not on acceleration or grades. It'll lose vacuum and HVAC falls back to its spring loaded default Defrost.
    If it's like most newer Ford trucks, Problem is NOT the Select Valve. If it was, you'd likely hear it hiss behind the dash. But I'm 95% sure it's buried in the HVAC cabinetry.
    In the video, around Minute 11, the camera's in the passenger side footwell, and you see where the poster cut a vacuum line coming OUT of the lower right corner of that part of the HVAC cabinet. What Ford did, was bring vacuum from its source (engine if it's gas) INTO the HVAC on the Engine Compartment side. Then within the HVAC, is the Reserve Tank and the Check Valve. HVAC has to be completely dismantled to get to them. What I and many others have done, is find the Source under the Hood. Then run new vacuum line into the passenger compartment. You don't connect it to the side coming out of HVAC, the stub in that video. You connect to where it routes up to the Mode Select "Switch" which is actually a Valve. Then, under the Hood, connect a Vacuum Check Valve and Vacuum Tank to that Source you found.
    The one I fixed is a Ford "van" like the one in the video. Source is RED coming from the Engine area, and connects to Black to enter the HVAC, passenger side, near the Blower Motor. Here's a Thread I did on ours. Remember it's Van not Truck, and Gas not Diesel. http://www.batauto.com/threads/2002-ford-e-series-van-a-c-always-defrost.13532/
    Do some research before you tear the Dash apart!!! I didn't and most of the start of my thread is wasted effort. I didn't watch the whole video, but I think the work through that access panel in the top of the dash isn't needed either. You'll find video on video, post on post, describing the condition I'm telling you about. Find the Source. Disconnect and see if you have vaccum. If you do, go inside and make that cut. Leave a little stub to connect back on the rare chance I'm wrong about this. Then take a length of new vacuum hose and run it any way you can, like Hood and Door Open. Connect under hood end to Source and inside connection to the piece you cut off. Start'er up. I think you'll find the system works. Then you need to find a Tank and Check Valve, where to run the Hose, tidy it up and DONE.
    If that Diesel uses a vacuum pump, you may not need the Tank and Valve at all...
    EDIT: Tried to look up "Vacuum Pump" for your 1999 F350 Diesel on RockAuto and found nothing. Also found very little HVAC Cabinet stuff. In Emissions, I found this Check Valve [​IMG] and it looks like the Dorman version I bought for my E450 Van "nose" that's under our motorhome. Description refers to "with Factory Air or High-Low Vent" so that at least tells me you have vacuum controls. Don't be misled by the "Blend Door" stuff. That function uses an electronically controlled motor.
     
    Last edited: Sep 29, 2017
  5. BC

    BC Full Member

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    Awesome JD! I appreciate this info!! I disconnected the line coming through the grommet and pressurized it with about 20-30 psi and could here the air blowing inside the compartment. I then pushed the grommet through the hole and pulled the line up as far as I could go and was able to get the check valve up to where you can see it in the pic. The short rubber hose is so badly deteriorated the it crumbles in your hand. So I was going to plug the canister side up do to one side of the line is bigger and this way I wouldn't have to find a barb fitting to put in. What you think?
     

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  6. jd

    jd Hero Member

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    I don't understand your explanation of what you want to do. I take it the Check Valve you found, is like the one I pictured from Rock Auto for your truck. The hose on the black end, to the right, is Vacuum Source. With a Gas engine, the Intake Manifold someplace. With Diesel, maybe a Pump...? Then the White end of the Valve, the Left end, serves as a Tee. Where does the line that disappears straight down go? Where does the disconnected short line go? When you applied air pressure, which line were you were you sending it? We meed to tread carefully here, because I was unable to pull the Check Valve to where I could see it like you did.

    Unless Diesel is significantly different from Gas, you need a Source, a Check Valve, a Vacuum Reserve Tank, and a Connection to your HVAC Controls. It MUST start with Check Valve at Source. Beyond that, the sequence of the connections doesn't matter. Ford put Vacuum Reserve Tank in the HVAC cabinet. You can put it under the hood, behind the grille, under the dashboard, any place it'll fit.

    Your pic shows the top of the passenger side front fender, right? I found that I could straighten a coat hanger and use it to fish vacuum/wiper hose between fender, fender liner and body shell, to where the radio antenna cable came into the foot well area. Connected it to where the cut is at Minute 11 in the video or the picture in my thread. Then the other side of the tee went to the reserve tank. Some reserve tanks have a built-in check valve. I chose not to "simplify" my installation by using one of those since I had to bury the reserve tank where I didn't want to have to go if the check valve part failed. Which it did! I felt really smart having put it right where I could see it, reach it, change it. I think I damaged it testing with my MightyVac, producing more vacuum than an engine does, and over "pressuring" the valve. So be careful using air pressure! You don't want to blow out one of the Actuator "motors" or damage the Mode Selector.
     
    Last edited: Sep 29, 2017
  7. billj

    billj MR BILL

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    You may want to look at this older thread of mine. Might help?
    HVAC vacuum diagram for a 2006 E350 Super Duty Van
    Discussion in 'Domestics' started by billj, Nov 8, 2015.
     
  8. BC

    BC Full Member

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    Kev2, JD & Bill.... thank you for the help on this one I greatly appreciate it! The video helped me out quit a bit and then the info JD sent was a big help to finish this off.

    Found a rubber plug and put over the hole that was going to the tank reservoir & then pulled the line back through he compartment and cut out a piece of aluminium for the hole I hogged out earlier. Took some good ole 3m marine grade sealant and covered it all up. I ran the van down the road and works like a champ!
    Thank you for everything.
     

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    Last edited: Sep 30, 2017
  9. jd

    jd Hero Member

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    Glad it worked! If I understand, you have HOSE running through the HVAC Cabinet but are no longer using a vacuum reserve tank. Is that right? From the little I know about Diesel, I'd think that'd work. Then you blocked the "tee" part of the Vacuum Check Valve, and went right to the controls, routed through the HVAC. I think...
    Again, Good Job!
     

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