Speedtoys

All the way right is high fans and all cold.

If its not doing anything but blowing air...then there could be a problem...the solenoid under the seat, or its not plumbed in under the car.

SeanR

Yes, the car should be running. Rpms at 1500-2000 with the compressor on.

pcar928fan

You might want to think about getting (and READING) the manual...

You can really learn A LOT about your car in there!

BTW, if your front a/c is working right it will freeze you out! The rear a/c's are classically the problem for these cars. Proprietary lines and fittings that go bad and if you want to replace them (if you can even get them) they are a zillion dollars...

One of the main problems with our old cars is the heater valve that does not fully close when it gets old so some (sometimes A LOT) of hot water is going through the heater core ruining all the cold air you are producing by heating it up. That valve is under the air intake box IIRC and if you pull the box off you can manually close that up and then just be sure to put your climate control on full cold so it does not try to open that valve again...

dr bob

Rear AC cars need to be charged with the rear AC on unless you charge by weight. For those that look at pressure-tempertaure-sight glass, the load of the rear air will cause you to add more heat (and pressure) to the suction side, so you need to compensate a little if you want the just-front performance to still be good.

rgs944

That is what I was afraid of. We had the front AC on high but did not have the rear AC turned on when adding. We used the sight glass and pressure guage for direction to stop adding. So basically the rear side now shorted the front when I turned it on? Am I understanding this correctly. Still learning.

rgs944

I just took the car for another test run. Rear AC is ice cold. Front AC is semi cold. It sounds like I might have the problem that James is reffering to.

rgs944

I believe my valve is closing all the way. So I must just be low on freon on the front side now due to it being sucked to the back when I turned it on. That rear AC sure is strong though.

Speedtoys

There is no front side..its a full complete system..just with two evaporators.

If your rear AC was not on at charge, you may be low on R12..because that entire third of the system was not open.

rgs944

So if the system is a complet unit and the back is blowing ice cold, am I correct to assume that I likely have enough R12? So then I would be back to that heater valve. I was reading some threads that even though it may be closing it also may be leaking internally. Maybe I just need a new valve?

Speedtoys

We dont know, what you dont know.

If you guy filled it by the book by weight..you got what you got..and thats bout right. If he did not..we dont know, what you dont know.


Maybe...you need to buy a WSM.

rgs944

I found this in an old thread. I am really leaning towards the Ac having an adequate charge with a misfunctioning heater valve or setting motor flap. I will try this test in the morning when it is cool.



"it could be a couple things..but by FAR the most common is the heater valve is dying or dead...the typical failure is they no longer hold vacuum and allow hot water to constantly flow through the heater core....less common is an internal seal failure where it holds vacuum but a little hot water gets around it....or the heater valve works fine, but there is no vacuum reaching it & its open

Another common problem is the "setting motor" flaps that control airflow to the heater or evaporator core get out of adjustment.....also common, but not as much as the heater valve

try this test....when the car is cold (not warmed up)....turn the ac on max...if both front and rear are cold then the front slowly gets warmer as the car warms up...you found it

mickster

If you get the weight right and the heater valve, the next stop are the dampers in the dash. Notorious for failing and a bitch to get to. (Ironically they'll be a winter project for me!)

dr bob

Following what Jeff said, the key is having liquid available at the expansion valves. If there's enough to condense at one then there's enough for both. The lines fill with liquid to both expansion valves just the volume of the solenoid and the line to the rear expansion valve are added as liquid space when the rear AC is activated. You can verify at the sight glass.

The setting motor shifts the blend door to add or block airflow past the evaporator, routed through the heater core partially if the foam seals on the door are deteriorated. The seal should probably be a nice extruded silicone bulb seal or maybe a lip seal of some sort. Instead it's a foam that's glued on like a low-density weatherstrip. It tires with age, amazingly. A bit of leakage is all that's needed to warm things up.

rgs944

Ran the AC with the engine cold this morning and still the rear AC is much colder even just sitting in the driveway. I then checked the sight glass and it is cloudy. Dang it, If I just would have had that rear AC on when filling I could at least eliminate that. Now with it still being low on Freon I do not know whether I am getting heated air past evaporator from failing flaps or a failing water check valve, or if it is still just low on freon.

rgs944

I went above the fuse box at the heater box control. The flap is not working at all. When I push it shut it still does not seem to make a difference but I have not had the car up to temp either.