[302 Z28]

Thought this might be better in the electrical section. I have a Vintage Air Generation II system I installed in my 34 about five years ago. The car does not really get driven that much in the winter, but when it does I use the heat function. This is the system that uses servo motors instead of vacuum operated control. Problem is when I have switched from heat to cool the servo motor that operates the hot water valve will not close the valve totally which defeats the air conditioning. When this happens I can lay on my back on the passengers side floorboard and manually move the valve another 1/8" revolution to fully closed. When I do this I feel the servo motor helping me move it a little more. This leads me to the conclusion that the servo motor is just not strong enough to fully close the valve.

A little past history: After installing the system at the completion of the car I noticed the problem. I called Vintage Air to report the problem with the valve. They said it could either be the "cool-heat" slide switch on my control panel or the valve itself. They gave me resistance readings for the slide switch for open and closed positions and mine checked out fine. Called them back to report that there was nothing wrong with my slide switch so it must be the valve. My system was already about three years old by this point and Vintage Air was not willing to send me another valve at no cost (at least who I was talking to), so I purchased another one for about $70. It rocked on for one more season but when summer approached it did the same thing as the old one. I called Vintage Air back to again report the problem and was told there were no other reports of problems with the servo valve.

Back to present: I attended a local show this past Saturday with temps in the low 100's with the A/C not doing a very good job. Upon arrival I manually helped the valve to close which restored the A/C. Having been annoyed by this problem again I looked for cars with this system installed. I found three, two of which had installed a manual valve before the servo valve so they could shut off the hot water flow when the heater is not needed. The third person was aware of the problem but said he puts up with it and would not like the look of a manual valve so he did not do it. They all had contacted Vintage Air about the problem with the pretty much the same story as I had.

I plan on calling Vintage Air back tomorrow morning and letting them know I want a solution.

Vince

[ogre]

make sure the valve flow is correct, right line, right orientation.
i'm installing a manual valve in mine.
i bypassed it the first day of the hrpt,
my heater core is disconnected at this time.

on the plus side; we enjoyed cold ac in 104* heat

[bentwings]

I have VA too but a vac system as there isn't room under the dash for the mini Gen II. The vac heat valve works ok. I use it occasionally to help purge the motor. ie sometimes the motor gets up into the 220 range instead of the 205 it normally runs at. I just cycle the heat switch and let it run on heat for a couple minutes. this seems to cure the minor problem. Not sure why this happens.

Eventually most heat (water valves) seem to fail sticking partially open. I've seen many simply install a standard ball valve in the line. Oem ones seem to work forever but the aftermarket ones don't hold up. You may want to try a Zinc anode in the radiator to keep some of the junk from forming.

Frequent cycling of the valve seems to help some too.

[Joe G]

Vince,

The servo control modules on those units are extremely sensitive to less than perfect grounds. The control module ground is a 22 ga white wire that comes out of the VA harness with the mode switch wires as a ring terminal. Make sure that wire has a good dedicated ground.

If that doesn't fix it, you can install a switch that will let you select between full closed and automatic. I'll post more info on that if you're interested.

Hope this helps....

[302 Z28]

Thanks Joe, I am fairly certain it is grounded properly but that is one thing I will re-check. I also have a suggestion from a friend who installs these units in his rod shop and he has told me that in addition to a superb ground the servo also needs a full 12 volts to close it all the way. He has taken to installing a relay that will supply a full 12 volts to the close side of the servo...seems to cure the problem. We will see what Vintage Air says about it tomorrow when I call them.

Thanks
Vince

[Irelands child]

Vince - you probably don't recall, but 3-4 years ago when I was installing my VA, I had questions about the way that valve worked, NO, so I found a NC valve and wired it with a toggle switch all based on a 'conversation' we had here. This kept hot water away from the evaporator and that continual added heat. I have kept that switch and that valve in place now that I replaced the a/c with just heat - and it works fine. That servo valve IMO, is a VA weakness.

If I can find my spare, I'll update this thread, but that's in some of my treasures that are packed waiting our impending Virginia move (which, so far isn't happening)

Dave W

[302 Z28]

Yes Dave I remember that conversation and I tried to find the old post with no results. I recently became aggravated with this problem again so I thought I would bring it up.

I just got off the phone with Vintage Air and they do not acknowledge a problem with the servo valve. Their suggestion again was to check the resistance of the slide switch and if that is OK it is either the servo valve or the control board . As to Joe's suggestion of the insufficient ground they said if that were the case the other servos that control the doors would be acting up which they are not. The grounding of the servos is accomplished through the system ground and the servos do not have a dedicated ground.

I hope you can dredge up our old conversation so I can solve this annoying problem as Vintage Air refuses to believe there is one. FWIW, I have a close friend who is holding off the purchase of a Vintage Air system for his 69 Corvette until this is addressed.

Vince

[Irelands child]

Originally Posted by 302 Z28

Yes Dave I remember that conversation and I tried to find the old post with no results. I recently became aggravated with this problem again so I thought I would bring it up.

I just got off the phone with Vintage Air and they do not acknowledge a problem with the servo valve. Their suggestion again was to check the resistance of the slide switch and if that is OK it is either the servo valve or the control board . As to Joe's suggestion of the insufficient ground they said if that were the case the other servos that control the doors would be acting up which they are not. The grounding of the servos is accomplished through the system ground and the servos do not have a dedicated ground.

I hope you can dredge up our old conversation so I can solve this annoying problem as Vintage Air refuses to believe there is one. FWIW, I have a close friend who is holding off the purchase of a Vintage Air system for his 69 Corvette until this is addressed.

Vince

Vince - before I posted, I looked. I dumped most of my old stuff a while back so it's not a part of my subscribed threads. As a note, VA did replace my MODE and speed switches as the mode was very sloppy and was only intermittent. They are, I believe what operates the valve through that blank box called 'control module'. If you pull the dash panel off, you will find that these switches have only a riveted kind of connection rather then being soldered or brazed. VA sent me new switches at no charge even 2-3 years out of warranty. I fixed the mode switch by cleaning and soldering the terminals to the rivets - and it worked fine until the replacements arrived. If you want to try it, PM your address and I'll send it off to you





The valve I used is an EHCOTECH EEB-CS-12VDC.



Dave W

[302 Z28]

Dave that water valve is different than mine, that looks to be a simple on-off valve you have there. My hot water valve is controlled by a temperature slide switch that controls hot water flow into the evaporator via the control module. I am convinced that there is nothing wrong with my slide switch or my control module and the problem is endemic to the servo controlled hot water valve. Since Vintage Air is hesitant to admit there is a problem with that valve I guess I am resigned to installing a manual on-off valve ahead of the servo valve. I will just valve hot water in when the winter comes.

Here is a picture of the nefarious valve I am wrestling with.


Thanks
Vince

[Irelands child]

Originally Posted by 302 Z28

Dave that water valve is different than mine, that looks to be a simple on-off valve you have there. My hot water valve is controlled by a temperature slide switch that controls hot water flow into the evaporator via the control module. I am convinced that there is nothing wrong with my slide switch or my control module and the problem is endemic to the servo controlled hot water valve. Since Vintage Air is hesitant to admit there is a problem with that valve I guess I am resigned to installing a manual on-off valve ahead of the servo valve. I will just valve hot water in when the winter comes.

Here is a picture of the nefarious valve I am wrestling with.


Thanks
Vince

Vince - that's the 'on board' NO valve that VA supplies. The one I show is a separate in-line NC valve that when I shut it off via toggle switch it doesn't "care" where the VA valve is positioned. IT'S CLOSED!!!! Hot water wont flow. I had them both. Of course, a manual valve is as easy as a trip to Home Depot but anybody can do that - mine was just more fun

Dave W

[KMatch]

Any chance it's a calibration issue? My gen Iv required calibrating and I wonder if your problem might be related. Maybe a recal wouldn't hurt if it applies to the gen 2.

[302 Z28]

Got you Dave, sorry for the confusion. I know what you did now. I checked my slide switch and it is dead on. I pulled the plug from the servo valve and plugged it into my spare servo valve. Moving the temperature slide switch from cool to heat cycles the valve and it opens and closes fully. I removed the three screws holding the electronic part to the valve body from my spare one (which was the original one). I then removed the electronic part from the installed valve and placed the original electronic part onto the installed valve body, and lo and behold it cycles properly. I then disassembled the remaining electronic part and found a BROKEN GEAR. We will see how long this repaired valve holds up.

PS, I do like the method you used, it looks much nicer than a manual valve. I may end up doing that if this problem returns in the future.

Thanks for all the suggestions
Vince

[OLNOLAN]

Hey Vince, Here is the thread that cured Dave's heater issue if you need it. Nolan Vintage Air bi level heater

[302 Z28]

Hey thanks Nolan I really appreciate that.

Vince

[Joe G]

Glad to hear you got it figured out, Vince.

Originally Posted by 302 Z28

....As to Joe's suggestion of the insufficient ground they said if that were the case the other servos that control the doors would be acting up which they are not. The grounding of the servos is accomplished through the system ground and the servos do not have a dedicated ground.

What I was saying is that the control module needs a good dedicated ground. The servos ground through the control module. VA unfortunately has the control module ground wire coming out of the harness at the main control panel, where it is awfully tempting to just drop the ground ring terminal onto one of the control panel mounting studs - which is rarely a good enough ground.