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Discussion Starter · #1 ·
I have a vintage air system in my 57. It is the gen II style with a heat slider switch and a cold slider. Recently it started blowing both hot and cold (the heater became uncontrolled). I know its either the temp switch or the servo valve (when I pinch off the heater hose the AC is nice and cold - when I let it go the AC can not overcome the heater)

Any body know how to troubleshoot so that I don't just end up buying both control and valve?
 

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Discussion Starter · #3 ·
A call to Vintage Air should help. They are pretty helpful with this kind of thing.
they were very helpful - they gave me the name and address to a local authorized repair center - I may have to go up there - but so much for DIY. And my guess is it would be more cost effective to just buy both rather than pay someone else to tear my dash apart!
 

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I am with you John. VA should of given you more info. about what is wrong. They should know with what you told them.
Jeffrey
 

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I had the same problem. What I needed to do was, in one of the heater hoses I had to put a shut off valve, and in the summer close the valve so the hot water would not enter into the heater core. The in the Winter just open the valve again so the water passes by into the heater core for heat.
My valve is manual operating but I believe you can get an electric valve
 

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Do you have the heater water control valve in place and working??
 

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Discussion Starter · #7 ·
The control valve is in place - but does not close - its on full flow at all times. I don't know if its the pot (slide temp switch), the valve itself or even the control module that lives between them. I could do my own trouble shooting if I could find HOW. A\C works great - I have full control over it - but it gets overwhelmed by the heater. I did place a rubber sleeve over the heater hose and clamp it off with my hose service clamp to get through the summer cruises - wqith A|C on high it was plenty to even over come my wife's hot flashes (er um power surges) - but I want to fix it up right.

by the serial numbers this unit was sold (and most likely) installed in 95 and upgraded compressor in 2008 - I can't believe it did not at one time work properly - so that eliminates all of Vintage Airs troubleshooting help (valve installed in wrong hose or wrong direction). It comes down to an electrical component failure! Without something that tells me what voltage I should see at which wire and when - it's basically a crap shoot! Thats where VA will only refer me to a "qualified" tech (who may not even have the same certs I held - but has their TS data because he's their distributor!) Thinking I would start with the valve (easiest to replace) as I am doing a full service on the cooling system this spring anyway, then the pot (A little more difficult) and module last. But the problem is it could be any of the wires as well! I hate trouble shooting by replacement - it is just so innacurate!
 

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Does the valve close when you unplug it?
It can be in backwards.. If the decal telling that it has to be mounted in the opposite direction of the "arrow", is gone.. it may be.
 

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Discussion Starter · #10 ·
Does the valve close when you unplug it?
It can be in backwards.. If the decal telling that it has to be mounted in the opposite direction of the "arrow", is gone.. it may be.
Now thats helpful - so normal op is when the power is applied it closes? I will check that tommorrow.

the valve may have been part of the 08 upgrade.
 

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It..

Now thats helpful - so normal op is when the power is applied it closes? I will check that tommorrow.

the valve may have been part of the 08 upgrade.
opens when power is applied.
 

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As Chuck says it is powered open. First I would unplug the water valve feed wires and then run the engine and see if you still have water flow, either the valve is in backwards(I first put mine in backwards) or it is stuck open. You can at the same time check to see if you have voltage at the valve while the A/C is operating. There should be two wires, a feed and a ground, or a return to the controller. I hope this gets you some resolve, Merry Christmas.
 

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Discussion Starter · #13 ·
Update guys - I got some real help from VA.
on the genII the servo valve is not an open close valve - its servo positioned for full closed, 1/3 open, 2/3 open and full open - it has five wires to determine position.
the test out was rather simple. The pot (switch on dash) is unplugged and switch side tested using an ohmmeter applied across common and one wire, then common and other - as each wire is tested the reading should mirror as the slide is moved off center. If not mirrored the pot is bad. Mine passed so we went to next step - the servo wires from the module are tested at the servo for voltage - Common to 1 then 2 then 3 then four as a helper moves the pot from cool to hot. Cool being NO voltage at any wire - as the pot moves toward hot the voltage should apply to 1, then 2 etc to open the valve further incrementally. My test passed - servo is bad (best guess is valve stuck open - servo toasted trying to close it - the cooling system is full of stop leak to hold the original radiator together - unless it somehow re-installed itself backwards by itself to go from working system to non - we can rule that out)
 
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