There should be a connector where RED plastic tubing comes from above the engine, and joins BLACK plastic tubing that disappears into HVAC cabinet. If you run rubber vacuum hose (I got 5/32" but 1/8" might work) from the RED around to inside the van, just through the open passenger side door, TO where I said Cut the Black from the HVAC (rhymes, but I am NOT Dr. Suess...) you should find the controls will work.
THEN, supply vacuum to your new tank from RED through a Check Valve. Then on to inside the van. I'd say get to the passenger side any way you can then fish it between fender and fender liner, to the door post (near the hinges). Forward of the hinge you'll find a large plastic body plug. Take it out, pierce it for the new hose, and push through to the inside. The plastic toe kick trim will have to come off, but that's all. Connect to where you cut. It'll be BLACK tubing coming down from the top of the instrument panel.
I like where I put Acme Roadrunner Bomb on Passenger side because:
1. my wife saw the spot and suggested it
2. much shorter hose runs than to, then from, the coolant reserve tank area
But you've got the plan and it'll work. Like me, you found it's not so easy to find even enough space for a little vacuum tank under a Ford Van hood. I was ready to get a hiker's aluminum water bottle, epoxy a nipple into it, and tuck that away someplace. Heck, leave it in the cup holder and tell folks it's reserved for the vehicle. That little hose feeds the refreshment it needs to carry on...
No reason your plan won't work IF IF IF the failure is the one that happened to me along with many other Ford owners.
I just hope your connecting point doesn't mean you've already torn the instrument panel and controls apart because you most likely do not have to. Looking more and more like you didn't get to the thread I linked in my first reply to this case. If you gOOgle "BAT 2002 ford e-series" you'll get to "http://www.batauto.com/threads/2002-ford-e-series-van-a-c-always-defrost.13532/page-3" (you can copy/paste that without the " " and get to it also) which contains the whole process, ACME and all. I replied thinking you HAD looked at that thread. IMO everything you need/needed is there. I used Dorman 47150 which has two vacuum "outputs" so it serves as a Tee. The Dorman 47077 reservoir, which you probably have the OEM of, has 3.5-mm ports, and that works out to about 1/8". Do I think the fix will work with 1/8"? Yes, uh...probably. it concerns me you'll run about twice the hose length than I did. But I'm sure that 3/16" hose will be too large for most of the fittings you're working with. GO ACME!
Jd. I have nothing torn apart. I just pulled the dog house off a couple times and tried to stick my head under the dash. Hard to do, broke my back about 6 weeks ago, now I have rods and pins holding my spine together. Sucks
I'd much rather hear you tore the van all apart than your back was torn apart. I helped a friend put an antisway bar on his RV and he seemed to do well. Then spent about two days in bed with his back. Has surgery 19NOV.
Look at my 2002 thread. Get enough hose to reach from the underhood RED down to where I show the cut line.
You can see the exit point from the HVAC cabinet. It's to the right of the mounting ear for the Recirc Servo. The line comes down from above, as I mentioned before, paired with the white line to the Servo. Connect those two and the system should work perfectly at idle. It won't work off idle or on a pull, but finding it working at idle is "proof of concept" that you've got it working by bypassing vacuum failure buried in the HVAC cabinet. In the above pic, the passenger side kick panel is already off. You can look and see where the Antenna Cable comes to the door frame and passes through it. Forward of that, there's the plug I punched to get the new vacuum hose through. I used 5/32". I don't like jamming a small hose onto a larger fitting, like 3/16" onto a 1/4" fitting. It may stretch and go on, but it cracks in short order.
Anyhow, once I found no vacuum where I cut the tube pictured, I used my MityVac hand vacuum pump to test operation and prove a new source would get it working again. I tried some surgical tubing I had on hand, but no go. Clear vinyl-looking stuff from an O2 generator. Apparently it collapsed under heat and vacuum, wouldn't run the controls. Had to get vacuum hose.
I should mention that the system is working on my van at idle and off acceleration while driving. As soon as you accelerate, the system diverts to defrost. So it will be hard to do any testing at idle. But I am sure that I'm on the right track. If not I'll put a claim into ACME
What'll you do? Complain it's a DUD and ask for a Live One?
I first installed a bad check valve. It did what you describe on our first post-repair trip. Replacement valve and it worked fine. Problem is, if Valve and/or Tank fail, it's still a full Bypass HVAC/Replace Both to get back to normal operation.
I picked up some 3/16" vacuum hose, a vacuum tee, some misc connectors, didn't have a check Valve. Advance Auto . I'll try NAPA. I'm going to be busy for a while so it may be à bit before I post back with an update
Advance had the 47150 "two way" check valve on hand along with one other number. VERY hard to find on their display rack. I didn't check any of the "automotive recycling facilities" and bought my ACME from them, but they had to order it. I found NAPA had ACME in stock but I'd already asked Advance to order one in.
BTW, happy remembrance day. both of our countries gave alot for this day to be remembered for the sake of stuffing dictators.
Lets not confuse that sometimes, we may also have to stuff some closer to home sooner than we think. Democracy is an idea, not a right, if we don't defend it. Kudo's to those who gave and still give!!!!!! And utmost, to those who suffer still from their bravery. May they find peace and help from others for their sacrifices.