Classic auto air questions

[Dino]

Hey guys I need some info on A/C systems.

My 69 has factory air but it was in pretty poor shape and since I wanted to upgrade to R134a, I bought some classic auto air parts off a member here.  I replaced the RV2 with a Sanden style compressor and have new hoses, a new expansion valve with 2 capillary tubes (one with a nut, the other bare), a thermostat with capillary and a drier with pressure switch.  What I don't have is instructions on how to hook all this stuff up.  
I ran a new wire from the bulkhead connector as the old one was cut.  According to the wiring diagram that one goes to the compressor.

Does anyone have a manual or can tell me what goes where?

Almost forgot, I am using the stock evaporator and metal lines and a new condenser from classic auto air.

[bill440rt]

Dino,
I still have the manual from when I installed mine. It was pretty simple & straightforward. Only thing I don't have is the template for the firewall for drilling the holes for use with their heater/AC box (my car was non-A/C).
Either:
A) I can photocopy & mail it to you.
B) I can scan it & email it to you.
or...
C) You can print it right here from their website: http://www.classicautoair.com/manuals/1-2066%20INSTALL%20INSTRUCTIONS.pdf

[Dino]

Thanks Bill!  I can't believe I did not see that file, my bad!

I was really confused where the low pressure switch would go as there is no provision for it.  I guess I need some sort of adapter to fit it in there.  I'll go over the file, slowly, and hope to get it cleared up.   

[green69rt]

Does 134 require different high and low Schrader(sp?) valves?? 

[Dino]

I honestly don't know.  It seems the more I try to find out, the less I do.

I still haven't figured out where the pressure switch goes.  It came with the drier #33317 but does it mount there?   I certainly don't have a provision for it on one of the hoses as the pfd says.

I'm confused...

[ODZKing]

I was told by the folks at CCA that the switch on the receiver dryer is not needed on this system.
In fact I was told by one guy (not Ron, he is fairly knowledgable) to "cut the end off and twist the wires together". Yuh, that is the look I'm goin' for!!!  
In any case, I transfered everything over to the new rec/dry.  
The wire to the compressor has to have a thermostat switch in between as the new compressors don't have the tstat built in. So the wire should come from the bh connector to the tstat then to the compressor. You can see the tstat on the fire wall wrapped around the one hose.

[Dino]

Thanks Bob!   

I found out yesterday that I don't have enough space to mount the thermo switch below the '70 style VR.  I wonder if I can drill two small holes in the firewall without drilling through the A/C-heater box.  Probably not.

Do you have one or two capillary tubes on the expansion valve?  I have two, one plain and one with a nut on the end.  I have no clue where that one goes.  I do have the old expansion valve that came with the parts I bought and it has only one.  Maybe I just need to cut off the one with the nut?

Unless the original A/C box or the new Sanden type compressor has a pressure switch, I'm pretty sure I need to have this.

The only 'new' classic auto air parts I have are the compressor, condenser, thermostatic switch, and the two long hoses.  The drier and pressure switch came from autozone, expansion valve came from Rockauto, hard line and A/C box are stock and short hose from drier to expansion valve came from ebay.  What a puzzle!   

[ODZKing]

You can see the expansion valve in the pictures.  2 for hoses and I don't remember what the heck that is on the other side there.
Also FYI, every thing on my car inside, switches, heater/A-C box etc. is all original to the car.  Only under the hood was upgraded to R134 system and what you see.

[green69rt]

On the Classic air site home page, at the bottom, there is a button for downloading the installation manual for their system and for a OEM system.   One of those might help.

[Dino]

On the Classic air site home page, at the bottom, there is a button for downloading the installation manual for their system and for a OEM system.   One of those might help.

They do indeed have two pdf files on there but neither keep any factory stuff.  The file for factory air cars starts with instructing to remove all A/C parts, including the stock controls, and replacing it with their stuff...but that's not what I'm doing.  I need a manual for the under hood upgrade kit and they don't have one.  At this point I just need to know what to do with the pressure switch and the extra capillary tube on the expansion valve.

Here's a few pictures of the drier and pressure switch and two small metal...thingies in the bag.  No clue what those are for. 

Does anyone know what the brass looking thing on the drier is about?  Should the switch go on the other side where the bolt is?  I just don't know what to do with this stuff, there was no instructions with the drier and the classic air type has the switch on a hose.

[ODZKing]

There is an in and out and the switch goes in fron so it can only go one way.  I'll take pics of mine when I get home.

[ODZKing]

OK, here is a pic of my old one, you can see comparing the new one the in and out. One is male, the other female.
I had to use my old switch because the new ones thread size was different.
In any case here are the pics.

[WHITE AND RED 69]

Yeah the instructions are pretty useless for a setup using stock a/c locations. It took a few phone calls to get mine setup right.

On my drier the bolt stayed on and the brass fitting was where the switch goes in.

Don't know why the expansion valve has 2 tubes? Should only be 1. I wouldn't cut it though, just wrap around with the other tube.

I didn't want to drill in the firewall for the thermostat switch either so I used one of the blower motor bolts. Just had to make the hole a tad larger.   

[Dino]

Thanks gentlemen, it's starting to make a bit more sense now.  Good idea using the fan bolt, I'll have to do something like that.   

Yesterday I decided to unscrew that brass thingy, I probably shouldn't have as it went psshhhhh.   

W&R that is the same spot on your drier where your switch is, but the fitting on my switch is smaller than the drier fitting.  Did you get an adapter?

[ODZKing]

Mine is a 73 so I had a bunch of holes already one the firewall, only had to drill one. It fit perfectly in that spot and there is nothing behind it except the wiper arms.
I did think of putting it lower but my engine bay is REALLY hot. As it is I had/have to wrap more of the goo around it because it wouldn't cycle off and my system was freezing up. So I thought that a bit too close to the manifolds.
I did the freezer trick so I know the stat works ... just have to wrap it with more insulation.
I also found some nice Mopar style connector ends so I didn't have to use those cheezy Radio Shack ones they sent.

[Pete in NH]

Hi Dino,

I think Classic Air gave Bob some really, really bad advice about not needing the low pressure cut off switch, here's why. more modern compressors like the Sanden depend on the R-134 to carry oil through them to lubricate them. No R-134 , no oil through the compressor and it will quickly grind itself into aluminum bits. These bits will mostly wind up in the condenser and will plug it up. New parallel flow condensers are impossible to flush out. So, after the compressor destructs you wind up replacing both the compressor and the condenser. Then you have to try and flush out the rest of the aluminum compressor bits from the rest of the system. Classic Air's advice might be good for replacement parts sales but, not so good for your wallet. The old RV-2 had its own internal oil sump and oil pump to provide its own lubrication so it wasn't too sensitive to this issue. No oil Through the Sanden is fatal.

The low pressure switch should mount on the receiver /drier as Bob's  and W&R's pictures show. I can't see from your pictures of the drier if there is a small pipe plug opposite the brass pressure relief valve. That is what that small brass thing is. A safety valve to vent off system pressure if it gets way too high. That Psssst sound you heard was the nitrogen fill in the receiver/drier escaping. Receiver/driers are shipped tightly capped and filled with nitrogen as they will readily absorb moisture and quickly saturate with water vapor. That is, after all their job.

You need to run the capillary tube from the thermostat switch down into the evaporator fins. It's job is to keep the evaporator from freezing up. It is wired in series with the low pressure cut off and compressor clutch so it will cycle the compressor on and off. The old RV-2 had an EPR valve behind the suction port to do this same job.

The two capillary tubes from the expansion valve run into the suction side line and are shown in the FSM. If you need a scan of the page let me know.

In assembling your system, the receiver/ drier should have been the last thing uncapped and installed and the compressor second to last as the PAG oil for R-134 systems also absorbs moisture like crazy. To properly install the compressor it's a good idea to dump out whatever oil is in there and pour some of the proper weight PAG oil in the suction port. Then turn the compressor hub manually to circulate the oil. Them dump that oil out and refill with the specified amount and weight of new PAG oil. Reseal the compressor ports while installing the compressor until you get the lines in place. I have a Sanden manual around some place and should be able to find the amount and weight of PAG oil for your compressor if you have the model number.

This is getting bit long , but, I'll be happy to walk you through installing and charging up your system.

[ODZKing]

Pete, thanks for the explanation.  And yes, I have no idea why that guy @ CAA said that.
In my picture, you can see the line from the switch to the tube. Is that the best place for it or should I move that closer to the firewall on that hose/metal.   
That is exactly the issue I'm having ... freezes up after a long while. Ron @ CAA sent me another switch just in case but this one is working, from my freezer test anyway.  I simply believe it is not insulated enough, do you agree that could be the problem?
I was going to put more of that black stuff on the line as all the way up to the switch unless you have another suggestion or different product you can suggest.
Sorry Troy to hijack you thread!!   

[Dino]

Thanks for the explanation Pete!   

I found out that the pressure switch does go on the opposite side of the release valve on the drier so it's in place.  I hope I didn't mess up the drier by releasing the valve.  The compressor is dirty I'm sure so I'll definitely flush it a few times.  Do I need to remove anything or simply hold it upside down while spinning the hub?

I'm going to need a new thermostat switch.  I was drilling out the hole in the mounting tab so I could use the same bolt as the blower fan's ground wire.  I made it spin and snapped the capillary tube right off.  Oh well, it shouldn't be too pricey.

How do I run that capillary tube to the evaporator though?

I do have the FSM but I didn't even think to look there for the dual capillaries on the expansion valve so I'm going to read up on it now.

[Dino]

Would any of these work?  Besides having the terminals in different spots, I'm not sure if there's anything else different that matters but if anyone knows a better one to get, I'm all ears.

http://www.ebay.com/itm/A-C-Thermo-Switch-Thermostatic-Switch-UAC-SW-3123C-/131127933076?pt=Motors_Car_Truck_Parts_Accessories&hash=item1e87d57894&vxp=mtr

http://www.ebay.com/itm/A-C-Thermo-Switch-Thermostatic-Switch-UAC-SW-3122C-/131127933259?pt=Motors_Car_Truck_Parts_Accessories&hash=item1e87d5794b&vxp=mtr

http://www.ebay.com/itm/Global-Parts-Distributors-1711289-Thermostatic-Switch-/231257283238?pt=Motors_Car_Truck_Parts_Accessories&hash=item35d8021aa6&vxp=mtr

So as far as wiring goes, I run the blue wire that comes from the bulkhead connector to the thermostat switch, from there go to the low pressure switch and from there to the compressor.  Should I stick a relay in there somewhere or will this work?

Since this morning, my car has working A/C controls and a working heater valve again.  Woohoo!    

[ODZKing]

Since some of the items are CAA product, you may want to give them a call and see what they suggest. IF you call, ask for Ron ... he seems to be the only knowledgeable guy there.
Email is Ron@classicautoair.com or 877-342-5526 x 7022.

[Pete in NH]

Bob and Dino,

Dino, I would think you could use any of those thermostat switches you found. You can also get them in a type that is adjustable and that may be a good option so you can dial in the evaporator freeze point. The purpose of the switch is to turn off the compressor clutch at the point the evaporator will begin to freeze up.

Bob, I can see in your photo that the capillary tube on your thermostat is going into the insulation next to the suction line. Both you and Dino want to install the capillary tube actually into the fins of the evaporator inside the evaporator case. It is more common to mount the thermostat switch inside the car on the evaporator/ heater case and drill a small hole in the case to run the capillary tube down into the evaporator fins. Your evaporator is freezing up because you are not really measuring the evaporator temperature. You are measuring the suction line temperature after the evaporator. The evaporator has iced up long before you know about it.

Dino, I think your receiver/drier will be  okay as long as you did not leave it open for very long, like only a few minutes.. If you left it open and uncapped for a day or more I would replace it. If that compressor you have is a used one and has been open without plugs or caps over the suction and discharge ports you can not really flush a compressor out except with oil. Can you post a picture of the compressor so I can get an idea of what you're trying to work with? No relay required just wire the switches in series with the clutch coil.

[Dino]

Adjustable?  That sounds like a good idea, I'll find one of those.  

I had the drier open for about 10 seconds, no more.  I didn't think to run the switch on the inside.  I don't know much of anything about the A/C box so I'll have to check the FSM to see where to drill the hole.  Since I have the blue wire going to the bulkhead connector under the dash, can I interrupt it and hook it to the thermostat switch before it goes through the bulkhead connector and into the engine bay?  That way I don't have to drill another hole in the firewall.

Does the capillary from the expansion valve need to go inside the case as well?  That may prove a bit more difficult.  Also, I found in the FSM that there was a provision on the stock R12 hose to screw the capillary to, but the new line does not have that.  Can I wrap both of the expansion capillaries around the metal end of the liquid line like was suggested?

Here's the compressor, not my car but it's the one I have now.  I'll look for a part number if you need it.

[ODZKing]

Bob, I can see in your photo that the capillary tube on your thermostat is going into the insulation next to the suction line. Both you and Dino want to install the capillary tube actually into the fins of the evaporator inside the evaporator case. It is more common to mount the thermostat switch inside the car on the evaporator/ heater case and drill a small hole in the case to run the capillary tube down into the evaporator fins. Your evaporator is freezing up because you are not really measuring the evaporator temperature. You are measuring the suction line temperature after the evaporator. The evaporator has iced up long before you know about it.

Well, again that is where the folks at CAA told me to put it. If I would have known that it would have gotten done before the heater box went into the car.
Would it be any better on the other line or is inside the only option? I realize it's the best but not exactly the easiest now.   
To someone like me who has never done this before these instructions are confusing.  It sounds like a wire from the pressure switch goes to the thermostat.  But they told me just break the wire to the compressor and install the switch in between.

[Dino]

It is all very confusing, I'm scratching my head so much lately I think I dug a hole in my head.   

The A/C wire connects the compressor, thermal switch, and pressure switch in series.  It does not really matter from an electrical standpoint where one is in relation to another, as long as all three are hooked up and receiving power.  That's all it is really, the compressor needs power to spin and either switch is a safety on the line in case something goes wrong.  It's those damn capillaries that have me going every which way. 

I too don't look forward to digging into the A/C box but it has to be done I suppose.  Oh well, it's only more time and money and I have plenty of neither.   

[Dino]

I guess one of these would work  It doesn't mention adjustability but I don't know what else the rotary knob would be for.

http://www.ebay.com/itm/Global-Parts-Distributors-1711239-Thermostatic-Switch-/380813714101?pt=Motors_Car_Truck_Parts_Accessories&hash=item58aa4422b5&vxp=mtr


I'll have to crawl under the dash to see how to get the capillary tube in there.  From what I can tell from the FSM, it has to go in from the top and go straight down between the fins.  Oh boy...