2002 Ford E-Series Van A/C Always Defrost


Hero Member
Overcome by Weather and Other Events. Based on what I've seen so far:

1. No sucking/hissing sound under hood or in the dashboard area.
2. The Black vac supply line is clear of the Battery. I've seen these lines get crushed on a TBird we had, and replacing the battery was the cause.
3. It's really a good diagram, shows the function of the Select Switch (valve) in various positions.
4. I find the description of Vacuum Tank (where it's located and how to access it) very confusing. All this is crammed into a van-style dash/instrument panel/HVAC compartment area. Behind an Air Bag, too. It's gonna be hard to trace much of that Black Hose, but I'll get after it.
5. I'll come up with a vacuum source and verify the servos will change modes with that temporary vac source.
6. Was hoping all I had to do was access the Switch and source a replacement. Ahhh...

Run a vacuum hose from the engine to the control head. If everything works at idle, just plumb in a check valve and vacuum tank at a convenient location. No need to be Ford-Proud, any brand will do. Some tanks have the check valve built into the tank.


Wrench. I help when I can
Run a vacuum hose from the engine to the control head. If everything works at idle, just plumb in a check valve and vacuum tank at a convenient location. No need to be Ford-Proud, any brand will do. Some tanks have the check valve built into the tank
I totally agree with this!! Also, screw ford for having engineered this!!


Hero Member
Any chance this is an Epiphany? Last night I was telling the wife:

"Ya Know, I can run a hose from A to B and see how it works - Can always add a vacuum tank if it diverts under too light a load"

So I look on Amazon for "Vacuum Reservoir" and the only one they carry is that black plastic Sphere that GM used all those years on all those vehicles, $12. I read "Reviews" and let me paraphrase this one:

"Ford wanted $1000 to fix my A/C controls on a 2000 E250. I bought this tank and it works better than new"

Last night I was out with a flashlight trying to figure out where to mount a 6" hard plastic ball. Wrote Dorman and they say it's 157mm, so more like 6-1/4" Couldn't see any under-hood or behind-grille space that size. Still have a trim panel at passenger's knees to look behind but I doubt there's that kind of room. Saw one on line for F-Series and the reserve was flat, about the size/shape of a "bank bag"

Pretty sure I won't tear it down like Ford would.

Major boat problems I need to fix in a week too, so....

... Case Pends...


Wrench. I help when I can
I love these threads, especially when the OP is assiduous. I did my own research and since I have worked on many foreign cars, remembered the germans mercedes use a similar system and found this link http://www.germanimportsllc.com/12achecova3v.html, which resembles your check valve. Only 5$ online, 8$ at the dealer. As for availability, not sure, but should work with that reservoir you have.

Source vacuum to yellow, and source out to tank and selector switch, and you won't need to open the evaporator core case. I am sure there is room in the engine bay for the vac tank and routing rubber vac lines is easy as pie. Cheap too!! And will last forever. :idea:;) Then you can move on to diagnosing the selector switch. But From what I read from this thread, if you don't have that black line vac at selector, no go, no fun and opening up that evap core sucks large. Pun intended. I know my english is not always good, but I hope this helps you to resolve the issue cheap and fast.

JD, you rock!! Wish we had more members like you. I too had a job to do today, was supposed to check out a mercury outboard and it hailed this morning, I think we are getting the but(had to edit, butt takes two t's :confused:) end of the texas storm I saw on the news. Took a while to get here, but now it is raining cats and dogs. Sometimes I hate quebec. I think that is why so many quebecers go to florida for retirement!!:D
3 way check valve for mercedes.gif
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Wrench. I help when I can
I also found this and I would not want to do this procedure, so I think bypassing the whole check valve and tank to get vacuum to selector switch would be the best/cheap route.

Not my writing and here is a link. http://www.justanswer.com/ford/5ewef-ford-hello-2000-ford-van-e350-super-duty-1ftse34l0yhb80142.html

It is showing a 3 way check valve it must be internal to that evap case.

  1. Disconnect the battery ground cable.
  1. Remove the suction accumulator/drier. For additional information, refer to Suction Accumulator in this section.
  1. Remove the nuts and reposition the manifold absolute pressure sensor and bracket.
  1. Remove the nuts and reposition the vapor management valve and bracket (5.4L and 6.8L).
  1. Disconnect the condenser to evaporator tube from the A/C evaporator core. For additional information, refer to Spring Lock Coupling Disconnect and Connect general procedure in Section 412-00.
  1. Remove the screws and the suction accumulator bracket.
  1. Loosen the clamps and remove the intercooler tube (7.3L diesel).
  1. Remove the screws and remove the evaporator core housing support bracket.
  1. Remove the 11 screws, release the 3 retaining tabs and remove the evaporator core cover.
  1. Remove the evaporator core.
  1. To install, reverse the removal procedure.
    • Install a new A/C evaporator core with the correct amount of PAG Refrigerant Compressor Oil (R-134a Systems) F7AZ-19589-DA (Motorcraft YN-12-C) or equivalent meeting Ford specification WSH-M1C231-B. For additional information, refer to Section 412-00.
    • Install new O-rings lubricated in clean PAG Refrigerant Compressor Oil (R-134a Systems) F7AZ-19589-DA (Motorcraft YN-12-C) or equivalent meeting Ford specification WSH-M1C231-B.

Read more: http://www.justanswer.com/ford/5ewe...per-duty-1ftse34l0yhb80142.html#ixzz3eCSOQjsb

2011-08-15_141210_vacuum_tank1.jpg 2011-08-15_141210_vacuum_tank1.jpg


Wrench. I help when I can
Opening up a AC unit and paying for all that is useless if it is just the check valve or the tank in my opinion. Maybe someone else here can chime in and give you better advice, but this is all I got for you at this point. Post back when you have vacuum at selector switch and if the defrost/vent mode won't work, we will work further with you. Again, wish all the guys that come here were like you!!;)


Wrench. I help when I can
Pretty sure I won't tear it down like Ford would.

Major boat problems I need to fix in a week too, so....

... Case Pends...
So hope to hear from this thread before summer ends, lol, and I am sure you will get her done.




Hero Member
I'm a 45+ year member of US Coast Guard Auxiliary, and we run our 21-ft Sea Ray "Pocket Cruiser' (a sport boat with a little cabin) on safety, regatta, and rescue missions. Power's a 5.7L V8 (Chevy 350) with MerCruiser stern drive. Here's what happens when I hire somebody: Outdrive installed with O-Ring out of place. Pumped salt water through the shift cable to the starboard side of the engine, where it ran down over the starter and into the bilge. We also had an engine-mounted circulation pump go out, and salt water got into belts and pulleys. I got a set of good used pulleys and cleaned up the rust that wasn't pulleys. Go to paint the "bottom side" of the harmonic balancer, starter runs but doesn't engage. The way the engine's installed, took me about 4 hours to change the starter. Had a spare on hand, have since restored the take-off to be the spare. Anyhow, this morning I got all the pulleys and belts installed and it's running again.

There was only about 30 mics for the E450. I measured the OD of the plastic lines, 5/32" and I think Mrs.jd spotted a place I can mount the vacuum "ball" by removing the air filter housing and mounting it under the cowling in the "V" of the engine. Then I pulled the trim at passenger side knee level. Yelled FORD and pulled. Came right off. Behind that there's a metal plate that unbolts. I don't think there's room for a Vacuum Tank, but I found a couple vacuum lines and a connection point. So there's a couple more places I can test, but for now I can say a Black Line (and Black should be Supply) leads through a grommet into.... Evaporator Core Housing (that I've been calling the HVAC Cabinet).

Now it's getting interesting! I WILL fix this Sucker! I will NOT go through the gyration shown above NOR will I hire Ford to fix it. I'd rather Push a Ford than Drive a Chevy. That's Ford Proud.

Thanks for the encouragement. Victory is at hand.


Hero Member
Saturday Morning Update: Lordy, it's Sunny, Hot, Sticky Humid. Oh, the E450 project:

Removing a crash panel trim, the plate behind it, the bracket behind that, along with the kick panel trim, I was able to find where the Black tube (supply to the HVAC Control Knob) comes out of the inside of the HVAC cabinet, secured with a grommet. A nearly inaccessible connector joins that Black tube to the supply tube for the Knob, and the White tube that's for the Recirc Air servo.

Got out my MityVac. Suction on either end of Black (at supply connector under hood, or coming out of HVAC cabinet) with other end plugged, produces LEAK. The MityVac can't create any suction. This tells me the Tubing, and/or Check Valve, and/or Reserve Tank (all of which seem to be buried in the HAVAC Cabinet) is LEAKING.

Proof of Concept. Plugged tube connector back onto Select Valve. Used MityVac to supply vacuum to the Valve. Started Engine with A/C switch on. Supplying external test vacuum to the Valve lets me change Modes. All but Recirc since that two-hose connector is disconnected to supply vacuum at the Black tube.

Modes seem to hold without pumping the MityVac till changed with the Knob. This suggests the system might work OK with only a Check Valve, once I bypass the leak(s) in HVAC cabinet. I can certainly try it, and add a Vacuum Reserve Tank later. Once I figure out where.

Going to find or make a hole in the firewall...


Hero Member
That black line coming out of HVAC Cabinet has a built-in grommet. I can pull that free and when I do, there's a large object a couple inches down the line. No doubt it's the Check Valve. A guy with more nerve than me could make an access hole in the cabinet big enough to disconnect what's there and connect the tubes together. Then fasten a repair patch over the access hole.

I found that Mercedes vacuum check valve at the link listed and at Amazon for about half the price. Amazon's prime price is 2X the other site, but that site's shipping/handling makes it work out to 2X Amazon's price.

Price aside, do you know the Tubing/Hose sizes the German part connects to . I'd like to see it to fit 1/8" (3mm) tubing. The hose connection on the Dorman 47077 Vacuum Reserve Tank I'd like to use. The plastic tubing on the vehicle now is 1/8" (3mm) Outside Diameter. If I can match those to the Check Valve then I can put it all together without size adapters.

Found a way to route hose from the underhood source line to the connector by the HVAC cabinet by going inside the fender than in through a grommet in the door post (near the hinges). Now to just do it. Will have to order parts...
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Hero Member
Your Advance link led me to the BWD/Carquest EC101 vacuum reserve. I think I'll ask them to get me one of those. It has more the look of a tuna can than the big sphere so common on GM and about the only replacement Dorman carries in Help! line. Tomorrow after church I'll look in on Advance.

I've got a strategy for anybody who starts a thread on this issue. Find the black tube coming out of the HVAC cabinet in front of passenger's feet. Cut it and see if there's vacuum on the HVAC end. If none, run a bypass line, check valve, tee and vacuum reserve. If there IS vacuum, OOPS, sorry, splice it with 2" of 1/8" ID vacuum hose and start digging.

I still have no check valve and no reserve tank, so I need to get more parts AND find out where to put the reserve tank.