Anyone have a picture or can describe how the air hoses are routed from the heater blower discharge elbow to the two exhaust heat exchanger blower air inlets? When I got my 412 wagon, it didn't have the hoses in there, the inlets on the exhaust heat exchangers were taped up . I do have a thinwall plastic "tee" that was tossed in the glove box, and appears to be part of the heater air supply system (it's the right OD), but I can't see how it all fits. The Haynes manual shows a neat-looking plastic "wye" fitting, so I'm confused . I do know it's different from the sedans, since there's one blower discharge fitting and two exhaust heat exchanger inlets on the wagon version, whereas the sedan version has two blower discharge fittings.
Lane
73 VW 412 (the Nomad, dropped valve seat land now, argh!)
67 MGB (Abingdon's Finest)
76 Plymouth Duster /6 (runs like a top)
99 New Beetle 2.0 (never gives any trouble)
04 Golf TDI (45 MPG)
09 JSW (love it, love it, love it!)
My 412 is 1000 miles away right now, so I'll try to describe this from memory. The heater blower in the wagon has a single square exhaust port, on which goes a plastic "wye" fitting that is held in place by a square aircraft-style clamp. (If you don't have the clamp, put it on your scrounge list. The fitting slips off all the time without it.) When the fitting is connected, the wye outlets are one over the other, versus side by side. Also the heater blower originally had a flap on the single exhaust port--yours may be gone. If the flap is there, the wye fitting should not impede it's movement when installed. The flap is supposed to be closed to prevent normal heating air from escaping through the blower motor when the blower is not running.
A tube must go from each wye outlet to a heat exchanger inlet, of course. Originally VW used an outsized ribbed plastic tubing that is extremely flexible--a quality very useful for the connection to the driver's side heat exchanger. Many 412s that I have seen no longer have the original tubing as it has long since cracked and become unpatchable. Sometimes you can find the tubing at the VW swaps or when a Type 4 is parted out. Many now have a Rube Goldberg substitute--standard VW paper hose in the middle, outsized baywindow bus paper hose sections slipped over the ends in order to mate with the wye fitting and the heat exchangers.
Which leads to where to put the hoses. On the driver's side, a hose from the plastic wye fitting will corkscrew in a tight spiral directly into the left heat exchanger metal inlet. This will be easier to do from one wye fitting than the other--you'll figure out which. The tight spiral is hard to do with any sort of paper or foil replacement hose without constricting the air flow. Whenever I've had to jury-rig a replacement for this hose, I've used plastic VW watercooled hoses of the closest length and shape that I could find at the VW swaps. The hose to the passenger side heat exchanger is easier to do. It goes along the rear (rear is rear) of the engine compartment as much as possible - under the coil, up over air bellows (See that pull-tab on the top of the bellows? It may still have its original plastic tie on it to tie around the hose!), along the alternator. Finally it fits horizontally into a bulbous plastic sleeve that sits next to the lower air cleaner housing. This sleeve connects to the right heat exchanger metal inlet with a couple of screws. Could that be the piece in your glove box?
I think that is about all. Let us know if you still have questions.
Thanks Chris and Albert, merci beaucoup! Chris, yibed what the Haynes manual shows, and it makes perfect sense. Albert, I'm looking forward to the images.
My blower was missing its check flap, and I fabricated one out of brass sheet and tubing.
BTW, the blower that came in my Variant had a thinwall plastic elbow (90 degrees) on the square discharge fitting, and the fitting I found in the glove box is a thinwall "tee". I wonder if those were scrounged from another type of VW (like a Type 3, or a 914)...anyone recognize the description? I'll post photos tonight, maybe that'll help.
Lane
73 VW 412 (the Nomad, dropped valve seat land now, argh!)
67 MGB (Abingdon's Finest)
76 Plymouth Duster /6 (runs like a top)
99 New Beetle 2.0 (never gives any trouble)
04 Golf TDI (45 MPG)
09 JSW (love it, love it, love it!)
Lane
73 VW 412 (the Nomad, dropped valve seat land now, argh!)
67 MGB (Abingdon's Finest)
76 Plymouth Duster /6 (runs like a top)
99 New Beetle 2.0 (never gives any trouble)
04 Golf TDI (45 MPG)
09 JSW (love it, love it, love it!)
I took a look at your pictures. My guess is that a DPO (in VW-speak, Dreaded Previous Owner) lost the plastic wye fitting, and someone later fabricated the thinwall plastic elbow and the fitting you found in the glove box to replace it. At least, it appears that the T-fitting could slip over the plastic elbox and provide connections for both left and right hoses to the heat exchangers. Does that look like it works?
My suggestion would be to put the wye fitting (and square clamp) on your scrounge list--it's a much more compact solution. I would offer to dig one up from my own stash (I THINK I have a spare) but it's all packed away now for a cross-country move.
I'm not sure about that. The elbow fits the blower's square discharge so well, it doesn't look fabricated...but it does look suspiciously like it's from another application.
Yes, the "tee" does look like it'd fit the elbow, but the outlet for the left exchanger is in the wrong place. That's what led me to ask in the first place. Maybe it'll work with some "corkscrew spiralling"!
BTW, what year is your Variant? Maybe it's a model year difference, too.
I'll add the "wye" to the junkyard list, and if you (or anyone) has one (or you get to the parts stash on the other side of your move, Chris), I'd appreciate it if you can give it up
Thanks again for the good info.
Lane
73 VW 412 (the Nomad, dropped valve seat land now, argh!)
67 MGB (Abingdon's Finest)
76 Plymouth Duster /6 (runs like a top)
99 New Beetle 2.0 (never gives any trouble)
04 Golf TDI (45 MPG)
09 JSW (love it, love it, love it!)
allo mg , for that , on one side on the blower , you have square fitting (2 1/2 direct on the blower with ( y) by 2 inchs round for air hose ,short hose go on lefgh side and on long on right . if you d,t have ,,original ,,,Y ,,,you can find at home depot section (shop vac ) or plastic plombery for same dimention ,,,albert
. I do have a thinwall plastic "tee" that was tossed in the glove box, and appears to be part of the heater air supply system (it's the right OD), but I can't see how it all fits. The Haynes manual shows a neat-looking plastic "wye" fitting, so I'm confused 
. I do know it's different from the sedans, since there's one blower discharge fitting and two exhaust heat exchanger inlets on the wagon version, whereas the sedan version has two blower discharge fittings.
