Need A/C help in Florida

[minifridge1138]

PS I need the High & Low side pressures after it's unplugged while A/C is running!!
Also just as well leave the gages on it,we will probly be doing more tests!! Plus I have a few more questions!!
6. When retrofitted,was the accumulator drier replaced??:confused
7. Was a New Orifice tube Installed??:confused
8. If so was there any trash in the old one??:confused
9. Was the complete system Flushed with 134a Compatible Flushing solvent??:confused
10. Was the old refrigerant oil dumped from the compressor and replaced with 134a compatible oil??:confused
11. What condition is the fan Clutch??:confused Is it Loose,does the fan have any front to back movement??
12. Is it Thermal or Friction??:confused Thermal will have a flat coiled spring on the front side!! Kinda like a Carburetor Choke Spring!!
My Toll Free is 1-877-677-2984 if it makes it easier!!

I will take a look tomorrow and let you know the high and low side pressures with the blower disconnected (as soon as I find the connector).
answers:
6) I did not do the retrofit myself, so I don't know what was replaced.
7) Don't know. Is there any way to know without taking the system apart?
8) Don't know.
9) I replaced the ac compressor about 1 1/2 years ago. It held a vacuum for over an hour. At that time, I put oil in system along with the freon (I had a more experienced friend help, so i'm not sure how many oz we put in).
10) When I put oil in, it was 134a oil.
11) AC clutch is fine. The engine fan (the one mounted to the water pump) is also fine.
12) I assume you are talking about the engine fan, it has the spring on the front, so I assume it is thermal.

I really appreciate all of the help so far, and can't wait for more great advice. I will take notes of what I do and the results so that I can post them here for others.
Thank you very much.

 

[gmjunkie]

I will take a look tomorrow and let you know the high and low side pressures with the blower disconnected (as soon as I find the connector).
answers:
6) I did not do the retrofit myself, so I don't know what was replaced.
7) Don't know. Is there any way to know without taking the system apart?
8) Don't know.
9) I replaced the ac compressor about 1 1/2 years ago. It held a vacuum for over an hour. At that time, I put oil in system along with the freon (I had a more experienced friend help, so i'm not sure how many oz we put in).
10) When I put oil in, it was 134a oil.
11) AC clutch is fine. The engine fan (the one mounted to the water pump) is also fine.
12) I assume you are talking about the engine fan, it has the spring on the front, so I assume it is thermal.

I really appreciate all of the help so far, and can't wait for more great advice. I will take notes of what I do and the results so that I can post them here for others.
Thank you very much.

There is No way to tell what Orifice tube is in it without breaking down the system!!

When you replaced the compressor did you replace the Accumulator Drier then??:confused

 

[minifridge1138]

No I didn't.
I had to replace the old compressor because my assistant ripped the electrical connectors off of the old compressor when he was changing a spark plug. It was in the fall and the system seemed to be blowing cold air, so I did not want to fix things that were not broken.

I got hung up at work and didn't have a chance to test the PSI with the blower detached.

I may decided to tear into the system this week. If I do, where is the orifice tube? I know it is in the the high pressure line, but that only narrows it down a little bit. I bought one for a Ford this afternoon.

Thanks!

 

[gmjunkie]

I may decided to tear into the system this week. If I do, where is the orifice tube? I know it is in the the high pressure line, but that only narrows it down a little bit. I bought one for a Ford this afternoon.

Thanks!

The Orifice tube is in the High Pressure Inlet of the Evaporator!!I wouldn't tear into it till some other things are checked!!
The Cheapest way to fix anything is to Diagnose the problem and fix the problem, Don't matter if it's A/C or anything else!! damoroso had allot more information on what had been done and what hadn't,He maybe thinks it still could be better but if he has 55 deg air coming out of the vents at Idle,He'll be dodging Snowballs in the passenger compartment after a 25 mile run down the road!!
Now there is any 1 of dozen things that Can and Will cause what yours is doing!! Lets Make sure what It or they are and Fix it,instead of throw Parts at it!!
As far as the fan Clutch,How do we know if it is OK?? We haven't really checked it yet!! Even if it was replaced yesterday it still needs checked!! Were going to check it's operation too,Like I said just as well leave the gages on it,We have Tests to perform!!
Also,are all the foam baffles between the Radiator and Radiator support??
This will also make a difference as to how well a system works at idle or slow speed!! If you have a Box or Window Fan,You just as well dig it out we'll need it!!

PS. I will be going to NE Missouri in the very near future and don't know how long I'll be there or exactly when!! Just depends on when I get the Call!!:eyerole:eyerole:eyerole

 

[gmjunkie]

Well I went to storage today and took some photos of A/C on my 81!!Haven't seen it for months!!


Below is a photo of the Blower fan and wire plug!! Yes it's tight,but if I can get a camera in there you can get it unplugged!!
Were going to check the compressor cut out pressure,and set it,I'm sure it was never done!! Most don't do it because they don't know it has to be done for proper operation!!

With Engine and A/C Normal running on low fan after obtaining operating temp and A/C stabilized disconnect the blower motor and tell me what the low side pressure is at compressor disengagement!!

Here is the Pressure switch!!

Now for Later reference the Orifice tube is Located in this location in the evaporator,You will be able to see it in the evaporator inlet after this Line fitting is removed!!

PS. My 81 hasn't been Retro fitted yet!!

 

[minifridge1138]

After work, I will do the following:
1) Hook up my gauge to the low pressure side.
2) Start the car and let it warm up.
3) Turn the fan on Low, AC on Normal.
4) When AC hits the lowest temp, disconnect the blower fan.
5) Measure the low side PSI.
6) Check to see if the fan moves freely after I shut off the engine (It doesn't move front to back, and I've never seen a leak).

I don't have any foam insulation between the radiator and the radiator support. I guess I'll have to order that.

How difficult is it to remove the blower motor? I've heard that putting in a motor out of an '84 will increase air flow through the vents.

Thanks!

 

[gmjunkie]

5) Measure the low side PSI.


How difficult is it to remove the blower motor? I've heard that putting in a motor out of an '84 will increase air flow through the vents.

Thanks!

After the engine is up to normal operating temperature,and the AC has run long enough to stabilize!! (10-15 min)
Then unplug the Blower motor and I want the Low side Pressure right when the compressor shuts off!!
We are going to set the switch!!

It's not hard to change the fan!! But we need to find out what is happening and fix it first!! Get the system Right and you won't need no Different Fan!!!!

And Yes it needs the Foam Baffles in it!!! Even if you have to make some out of Foam Pipe Insulation!!

All of these things "Will" effect the Proper Operation of the AC at low speed and idle!!

 

[damoroso]

Hey guys! You know, even @55 in the shop at an idle, the thing isn't blowing snowballs quite yet LOL!!! I think the issue now is air flow. I'm assuming minifridge is having some of those issues too because of the question about an 84 unit. My next project with this a/c unit is that I'm going to pull all the ducting out and re-seal everything. I know I'm not getting the air flow I should outta the vents above the instrument cluster. The air stops moving about a foot or so off the vents!!! I'll use the weather stripping I can get at home depot, it comes in a ton of sizes and is peal and stick. Plus it's about 2 bucks a roll!! That project'll have to wait for a couple months though, I just got back to Baghdad tonight (back to work!!) and I'm not due home till mid Sept. this time. Talk about needing a/c though, it was 130 when we hit the ground in Kuwait waiting for the flight to Baghdad!!!!

I'll keep watching the posts though, really interested in minifridge's fix!!

 

[minifridge1138]

I wasn't planning on replacing the blower anytime soon. I was just hoping that I could get your opinion of how difficult a project that is.

I don't think my ac compressor ever kicks off by itself. I would assume that at least one of the following is the cause
(a) my system is over charged
(b) my pressure switch is set wrong

But how can I find the low side pressure when the compressor kicks off, if the compressor never kicks off?

I was actually starting to think about custom made foam inserts. I hadn't thought of the foam pipe insulation, that's a great idea. I just want to make sure that whatever I make, it won't move as I drive.

 

[gmjunkie]

I wasn't planning on replacing the blower anytime soon. I was just hoping that I could get your opinion of how difficult a project that is.

I don't think my ac compressor ever kicks off by itself. I would assume that at least one of the following is the cause
(a) my system is over charged
(b) my pressure switch is set wrong

But how can I find the low side pressure when the compressor kicks off, if the compressor never kicks off?

I was actually starting to think about custom made foam inserts. I hadn't thought of the foam pipe insulation, that's a great idea. I just want to make sure that whatever I make, it won't move as I drive.

Once you unplug the Blower the low side pressure should start dropping!! If it don't were going to drop back and punt!!!:L:L:L Actually thats why I ask if you have a box fan or window fan !! If it don't drop low enough,you'll have to set the fan blowing in the front of the car like it's going down the road!! BUT I don't want it there yet!!

 

[minifridge1138]

OK, I unplugged the blower motor and the psi did start to drop.

When it got to 15 psi, the compressor shut off.
After I shut down the car, the fan on the water pump had resistance.

According to your earlier statement, to change the pressure from 15 psi to 21 psi, I should rotate the screw clockwise 1/2 of a turn.

At this point, the compressor will shut off at 21 psi, but my system never gets that low.

Let me know what I should do next, and THANK YOU FOR THE HELP!!!!

 

[gmjunkie]

OK, I unplugged the blower motor and the psi did start to drop.

When it got to 15 psi, the compressor shut off.
After I shut down the car, the fan on the water pump had resistance.

According to your earlier statement, to change the pressure from 15 psi to 21 psi, I should rotate the screw clockwise 1/2 of a turn.

At this point, the compressor will shut off at 21 psi, but my system never gets that low. I hope it will when we get done!!Actually it does,you just don't notice it while your driving!! If the ambient temp was a little cooler,it would be more noticeable!!
Let me know what I should do next, and THANK YOU FOR THE HELP!!!!

Go 1/4 turn first and then recheck it!! And we will go from there!! 1 1/2 lb is just a general rule,but each 1 is a little different!! Now check it again!!
PS Also look at the accumulator while the pressure is going down,is there any Heavy sweating or frost on it??

 

[minifridge1138]

You're the man.
1/4 turn and the compressor kicked off at 21.

I couldn't see any sweat on the condensor when I looked, but there was a puddle on the floor of the garage.
Also, I could feel some frost when I touched it (it felt like a nice cold beer).

With max a/c on, the air was blowing 67-68 degree air.

Umm... I just realized I had max a/c on the entire time, not norm a/c.
Is that a problem?

 

[gmjunkie]

You're the man.
1/4 turn and the compressor kicked off at 21.

I couldn't see any sweat on the condensor when I looked, but there was a puddle on the floor of the garage.
Also, I could feel some frost when I touched it (it felt like a nice cold beer).

With max a/c on, the air was blowing 67-68 degree air.

Umm... I just realized I had max a/c on the entire time, not norm a/c.
Is that a problem?

No not really,but it would stabilize quicker on Norm!! Real,Real Heavy Sweating or Frosting on the accumulator is what I was concerned about!! Thats usually a indication of excessive moisture in the system and the accumulator should be replaced!!Now if you have it all hooked back up,Put the AC on Norm with Medium fan and let it run and stabilize with the thermometer inside a vent!! After about 5 min or so I want the Inside temp and High Side and Low Side pressure!! Then set a Fan Blowing in front of the car to simulate going down the road!! After about 5-8 min I want the inside Temp and High and Low side pressures!!

PS I need the approximate Ambient Temp as well!!

 

[minifridge1138]

I'll get that for you tomorrow.
Too late tonight (i'll have to borrow a box fan).

It wasn't heavy sweating (I couldn't see or feel any with my hand, i just saw a puddle under the car).

 

[gmjunkie]

I'll get that for you tomorrow.
Too late tonight (i'll have to borrow a box fan).

It wasn't heavy sweating (I couldn't see or feel any with my hand, i just saw a puddle under the car).

There's going to be a puddle under the car!! Talk to you tomorrow!!

 

[minifridge1138]

Ok here are the numbers:

Outside air temp: 97

Without box fan:
Vent Temp: 63 +- 1
Low PSI: 25
High PSI: 225

With box fan:
Vent temp: 62 +- 1
Low PSI: 25
High PSI: 243

This was all with the AC on normal, and the blower on the 2nd click

 

[gmjunkie]

Ok here are the numbers:

Outside air temp: 97

Without box fan:
Vent Temp: 63 +- 1
Low PSI: 25
High PSI: 225

With box fan:
Vent temp: 62 +- 1
Low PSI: 25
High PSI: 243

This was all with the AC on normal, and the blower on the 2nd click

Ok,need to get some baffles around the radiator and then see what it looks like then,But I'm sure it is a little overcharged!!But the hard thing for you will be how to measure what your taking out!!Can't go very far at a time! And then you'll have to let it run and stabilize and check the Pressures and temp again!! I'd like to see the pressures at 97 deg with the AC on normal with the fan setting on the 2nd click around Low Side 22,High Side 200-215!! That should put your evaporator temp about 19-20 deg at compressor shut off!! But it still could have the small orifice tube in it!! I guess you would have to take a little out and see what it does,I know it will lower the pressures!!Remember just a little at a time and let stabilize,otherwise you can take to much out and the cooling will go the other direction!Also as you take it out there well probly a little frosting on the accumulator and evaporator outlet,But if there is at any frost on them after stabilization,the accumulator is likely to need replaced!!:ugh:ugh

 

[minifridge1138]

One thing I forgot to mention, I bought some PVC pipe insulation and made my own radiator seal. It isn't perfect, but it works pretty well.

I had a feeling the system was over charged.
I could complete empty the system, replace the orifice tube, and then fill it with the correct amount of freon.

The shop manual has 3 different values for freon. At the beginning of the AC chapter, it says 3 lbs of freon and 6 oz of oil.
Then in the system charging section it says the B Series uses 3.5 lbs and the G series uses 3.25 lbs. I have no idea which I have. I would also use 10% less because I'm using R134a and not R12

 

[gmjunkie]

One thing I forgot to mention, I bought some PVC pipe insulation and made my own radiator seal. It isn't perfect, but it works pretty well.

I had a feeling the system was over charged.
I could complete empty the system, replace the orifice tube, and then fill it with the correct amount of freon.

The shop manual has 3 different values for freon. At the beginning of the AC chapter, it says 3 lbs of freon and 6 oz of oil.
Then in the system charging section it says the B Series uses 3.5 lbs and the G series uses 3.25 lbs. I have no idea which I have. I would also use 10% less because I'm using R134a and not R12

I believe yours should be the first!!It should have the R4 Radial Compressor! Before 73 corvette used,I believe a Frigidaire A3 compressor which was a larger compressor,73-77 used a A6 compressor which looked about the same as the first but was a little shorter,78 -82 used a R4 Radial Compressor and required 6 oz. of oil,Like the one pictured below!!


Personally I wouldn't brake the system down if I could get it to work properly without!!Unless the compressor is noisy!!
And If I did have to in your particular case I would replace the Accumulator too!! (Have no Idea if or when it's ever been replaced!!) Rule of thump is if breaking system down and the accumulator is over 5 years old,Replace It to be sure!! If a compressor was destroyed or making noise,Absolutely Replace the Accumulator with New Compressor!! Chances are the accumulator has went bad and released the desiccant in to the system and plugged the orifice tube and Starved the compressor of oil causing the problem in the first place!!(Common Problem!!) (See Photo below!!)

If you want to break it down for piece of mind and to Absolutely Know the system will Cool properly,Break it down and put a Ford Blue orifice tube in it with a New Accumulator!! Then the only other possible problems with the system could only be Air Flow delivery from the evaporator!!

PS. Pore at least 2 1/2-3 oz of compatible oil in New Accumulator just before Installation!! And if your orifice tube has a major amount of trash in it,It needs completely Flushed with the proper Flush solvent!! I use a biodegradable solvent made from citrus. Don't forget the Pre-Charge Gages before charging!!