Hey Partners:

Looking for anyone that might have the issue I have with my A/C. My system is for a 68 El Camino SS with factory A/C and everything is brand new- Compressor, evaporator, condensor, dryer, expansion valve, hoses- BUT I have an ebay POA valve that "worked" and in fact was very clean inside and out. Here's my problem:

Went to charge the system today by a reputable a/c guy. The system was tested and was sealed- so the freon went in- this is an r12 system.

The air blowing at the vent is only 65 degrees at best on a 90 degree day today. When I move the selector lever fron "VENT" to "COLD", my blower motor only blows at the low setting- even when switched through med & high. When on VENT, all three speeds work fine.

Next, the evaporator is cold and moisture is condensing on it but the air output is not so cold. Inside the car , the a/c box is very hot to the touch. All the cables are adjusted and seals inside replaced prior to installation. Should this be so hot?

Last on the EBAY POA valve, there are two fittings that go into the evaporator area- one drains the oil, the other goes to a "bulb" I believe. On the POA valve, the fitting to the bulb, has a screw in valve like a "schrader" valve going into the POA valve- should this be there? I had a POA eliminator prior that had the opening wide open.

Any suggestions are welcome- by the way 90 degrees, high side 200, low 30 at 1500 rpm sitting idle.

Thanks
Rob

You may want to make sure all of your fittings are in the correct placement. With the oil line and "bulb" in the incorrect position it wont work correctly. The pressures seem to within specs. On my STV system a little different than the POA system, the oil line is connected to a shrader valve as well. The A/C box may be getting hot from the heater core. There shouldn't be any hot lines in or near the evaporator with regards to A/C except heater lines.

The fan issues may be an electrical issue. Im not real familiar with the 68 stuff, but there is a resistor in the top of your blower unit on the engine side of your firewall. With the A/C switched on power goes to it as well to change the fan speeds. You may need to trace the wiring, and possibly do some connector cleaning.

I know I didn't give any true help but its all I could think of. There are a couple of guys that are much more versed at Auto A/C than I am, I only took a couple of courses in college and have played around with fixing easy stuff, but its all I can offer.

Im having sealing problems and have to order a rebuild kit for my STV so I didn't get to go on my Chevelle cruise like I had been planning for over 4 months. Wife wont ride in a hot Chevelle and wont let the little one (3 months) go in it hot either. Its suppose to be 103* tomorrow.

You may also have hot water from the heater core causing the air to warm up before it comes out. Pinch off the heater hoses under the hood and see if it makes a difference. Could be the seal in the box are shot. If so, you can install a heater valve and just keep the flow shut off til you need heat, or loop the hose at the firewall.

I really think I have an air mixing problem. When I ride with the car in the "cold" position with the a/c compressor lead wire disconnected, I get very warm air just circulating- and a lot of it. Strange though, the fan works on low, med and high when the position is on "cold" and the lead wire disconnected. Once connected, when the selector is on "Vent", I get 3 speeds, if I leave it on high, then switch the selector to "cold", the compressor kicks in and the fan speed goes immediately to low and wont change.

Update- an edit to this- I did solve the fan issue, touching wiring on the relay. I did start the car- 75 degrees, in the shade. While it was warming up, got the a/c down to 55 degrees but as the heater core began to heat, the air began to rise. Any suggestions on what might be happening inside the unit with a seal in the mixing?
As for the seal between the hot and cold areas in the unit- Is there a seal between the two? I had the entire unit rebuilt by a very reputable vintage a/c shop in Orange County, CA. Could it be as simple as this?

Yes it could be that simple, the cold/hot cable could need to be adjusted as well. when you swap from cold to hot, do you hear the door closing or just moving? If the unit rebuilt, they may stand behind it and be willing to repair it, or at least take a look at it. When I get my AC working, I plan to put a hot water valve in just to keep hot water from being in the car in the summer months when its already hot enough.

You say the entire unit was rebuilt--do you mean they pulled the heater/A/C box out of the car and put in new seals, doors, etc. or did they just do the under hood stuff?
Here's an example of how the panels in the box deteriorate. When this happens, the air isn't diverted around the heater core and you'll get hot air. Les fixed his with heavy-duty aluminum tape used by home HVAC installers. See pics. Hope that helped.
BillL

Ok- I got home a little early for the 4th celebration and went through all my manuals and exploded views. I took out the glove box and disconnected the heat/cold cable on the unit and put it in a position where I could hear the door slam on the heat opening. Started the car and put the a/c on. With an outside temp of 85 deg, the car warmed up and I put the old meat thermometer at the vent. Sitting still at 1500 rpm, warmed up, the center vent read 52 degrees. I think I have a working system. Thanks all for the input- the road test will happen tomorrow- I'll see if anything goes.

Just for the record, the 68 model has no heater valve, the coolant alwa ys runs through the system. Since originality is an issue for me, I may not put one in but I am very tempted to tastefully install one for even better performance.

Thanks

Rob

I have just too much heat coming in the compartment from the heater core through the unit at the foot of the passenger. The 68 has no hot water shut off valve and the coolant always circulates through the heater core. I purchased a diverter valve and I decided to install it. Which hose do I connect to the valve? The one from the intake or from the water pump? It looks to be the same size as the one from the intake but just want to double check with anyone that might know- or have one- before I start cutting.
Thanks

Rob

the one from the intake.

Thanks Leo