Struggling with Heater Valve / Heater Control Testing. Super stumped.

No, but watch the video in post #83. Pretty much tells the story. Unfortunately, this company quit rebuilding them

 

Thanks I could reproduce the sliders in my company but need the pull one apart to get the patterns.

 

By the time I got done trying to resurrect mine, the originals were too mangled to be of any further use. I'm relatively sure we all are going to need these, its just a matter of when.

 

I'm having trouble with the HVAC buttons. When I got my Mondial, the electrical side on the HVAC button unit had overheated and fan did not work at all. I managed to breath some life to that, but now there are additional problems.

Problems I have now:

1. The button does not pop up anymore when another one is pushed down (this came up some time after the first time I opened up the HVAC button unit.). Found out this to be a mechanical problem due to my previous repair on HVAC button unit assembly.
2. Air re-circulation is on all the time, and I cannot switch air flow to windscreen vents. I think it has been like this since I got the Mondial.

I suspect that there may be different variations of the HVAC button unit. I had only three vacuum lines connected on my 1986 3.2 euro. Ports 0, 1 and 6. The qv maintenance manual vacuum connections do not match to 3.2. Page H31, fig 22. Notes are based on what I found on my Mondial.

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I did some trouble shooting with a syringe.
- When a syringe is pulled out and connected to the vacuum line from engine (connection no. 0), it the syringe retracts when engine is started. Vacuum from engine is OK.
- When I connect the syringe to vacuum line which would connect to port 6, and pull it to create a vacuum, I can see that a flap closes the dash vents. This works OK as well.
- When I connected the syringe to vacuum line which would connect to port 1, and pulled the syringe to create vacuum, I think I heard a flap moving. This is likely to work, but I did not have visual contact to flaps.

Both ports 6 and 1 will make the syringe retract when it is released, so I expect there are no major vacuum leaks on the lines or actuators.

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How exactly does the vacuum side of the HVAC button unit work? I took mine apart, and found out that the slots on the sliders are in the middle part, while the connection for vacuum hoses is on one end of the button thingy (left side on photo below). How is the vacuum distribution supposed to work? The design with the button mechanism doesn't exactly look air tight, and I cannot imagine how the vacuum would not leak if it is supposed to flow inside the housing.
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For time being I have bypassed the electrical switch. Now the HVAC system is powered when ignition is on. I also bypassed the vacuum side. When engine is running, fresh air flow from dash vents is activated. I would still love to get the setup working how it was originally designed to, even if it might be a bit optimistic considering the age and design of the HVAC button unit.

 

See the youtube video in post #80 of this thread -- it gives more detail about the internal construction and how it works (I'd wager one, or more of your "sliders" is broken). Even though others posted later on that Norwood stopped providing this service, might be worth giving them a shout -- maybe the demand got high enough for them to restart doing this.

 

Last time I talked to Norwood, they told me it would cost WAY over a grand apiece to make new units. They weren't interested. That was. a while back. Would be nice if that changed.

 

Thanks Steve, very good video indeed! I didn't take apart the sliders, so not sure if they are still in one piece or not. However they appeared to be of even length, so possibly still OK.

Even after watching the video I'm not sure how the vacuum is divided by the sliders. I understand that they change place when the buttons are being pushed, and even push up the previous button, thanks to the uphills and downhills on top part of the sliders. The small tab on the bottom of two of the sliders move the electric switch and the section at the vacuum ports. It would make sense that the section next to vacuum ports changes the vacuum connection. But what would then be the function for the small slots/dents in the middle part?

The electrical side of the HVAC button unit looks like this from inside, in case the information is helpful for someone in future.
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I assume it will be more or less similar idea on the vacuum side, even though I didn't take it apart.

Is Norwood still in business? Their web page didn't respond. If they could provide aluminum sliders, it would be extremely interesting for DIY people. That might be better business than rebuilding, if the cost for rebuild is so high.

 

Urs, are you still interested to reproduce those sliders ? Or, now that you moved, you do not have this possibility anymore ?

 

I still could but but don't have the actual shape/pattern. Someone would have to provide them to me very accurately.