The Queen customizes her 3.2

[echecsqueen]

Hi jsr3
The heating gizmos are open to ambient air meaning the flap is closed that leads to the heating ducts.
Walt- here are the pressures. 92 degrees outside in the shade. 95% humidity.

[echecsqueen]

Attached

[walt]

10 psi on the low side is too low should be 30+. Possible problem with the expansion valve but hopefully someone with more experience with ac will chime in. Unfortunately, it does sound like the system might need to be evacuated. A dedicated post will get more replies.

[smadsen]

I believe, but am not certain, the flapper in the heater boxes had a rubber seal when it came from the factory. If the seal is gone (dried out, cracked, turned to dust) you will be leaking a little very hot air behind the power of the engine fan. At 90 degrees ambient a little leak makes the cab very uncomfortable. I had to replace the wire from the lever to the flapper (a time consuming, tedious operation) to properly adjust, to get a metal-to-metal seal (without the rubber). That stopped the hot air coming out the cabin vent.

You might be able to find the rubber somewhere and then clean, paint & lubricate the flapper box, but it seems to work O.K. metal to metal when properly adjusted.

If you want to isolate the problem, disconnect the heater tube downstream from the flapper and see if the hot air stops coming out of the cabin register. If so, then you know it's the flapper mis-adjustment probably caused by the now missing rubber.

[echecsqueen]

Hey smadsen. You read my mind. I did disconnect the hoses from the boxes yesterday - essentially taking the boxes out of the equation. I had rehabbed the boxes on my 66 last year after having an incomplete closure of the flap and these turned out to be the same set up.
I am waiting on a new evaporator and dryer from Griffith. That includes a new expansion valve. I just didn’t want to put in a new equiptment and ruin it if the problem is something else. I don’t understand why a bad expansion valve would cause the evaperator motor relay to get hot hot (like too hot to touch) while putting out warm air.

[JRSIII]

At the risk of sounding obvious, it seems that you have something fundamentally out of whack. Upgrading to a higher efficiency evaporator may provide incremental improvement, but I think it's unreasonable to expect it will completely solve the problem if the system isn't functioning at all. Even a bone stock A/C system will provide some cooling. Have you verified that all of your air ducts and your A/C hoses are plumbed correctly? I'm sure you are aware of this, but the A/C air flow on these cars is separate from the heater/defroster system except for the side vents. See schematic below. I'd suggest you first close the side vents and measure temperature at the center vent if you aren't already, as the center vent is 100% dedicated to A/C. I'd be concerned about the evaporator motor relay getting hot. Maybe the motor is overloading. Have you pulled the floorboard and verified that the air path from the inside of the car to the bottom of the evaporator is clear? Are you getting good air flow out of the center vent? Is Griffiths sending you a new evaporator motor/fan with the high efficiency evaporator?
John

[tsuter]

By those gauge numbers the system is low on refrigerant and compressor may well be cutting off. (low psi cutoff)

Charging should be done on nice hot days:
1. With the engine at 2000RPM or slightly higher if the neighbors don't complain
2. Engine at operating temperature
3. Decklid CLOSED and towels blocking air leaks where the manifold hoses come out.
4. A big fan blowing air down into the grill...unless you got condenser mounted fans
5. AC on HIGH cold and HIGH fan!
6. Refrigerant gets added through the low side little by little...several minutes..

High pressure cutoff to the compressor (if your pressure switch is not faulty) is around 400PSI So the compressor will not cut off for high pressure unless you have no air through the condenser. Way too much refrigerant or something is plugged.

Low pressure charge for R134a is ambient temp based but say 90F then the low side needs to be close to 45-50PSI.

The low pressure cutoff switch is around 20-30psi!. Your compressor will shut off because of low refrigerant. Your pic shows 10psi..The compressor should not run.

If you have condenser fans then they should come on at around 240-260PSI and switch off at about 180PSI but this is based on the trinary switch design.

You can watch them work by dropping your RPM to idle and letting air in under you decklid. Pressures will jump and the fans will come on if set up correct. But at idle the fans may not be adequate to keep your high side from rising to compressor cut out.

[echecsqueen]

I appreciate the help guys. Here is where we are
I agree something is fundamentally wrong. That is why I spent 6 plus hours checking every aspect of the system.
1 worked normally until last month.
2 last month the temps went up and I checked and the pressure was barely low. So I added a can of Freon and the griffin barrier hose blew off of its ferrule at the connection to the rear deck condenser.
I brought the car in and my mechanic put a new connector on the hose , evacuated the system and replaced the Freon
Since the ac has always been mediocre I decided to buy the Griffith evaperator and dryer and front condenser. I already have the Griffith evap blower and hoses and bow tie in place.
In the meanwhile while waiting for those parts I had to drive the car. Despite it having Freon it is blowing hot air. I checked every component that I could think of yesterday. I checked all the ductwork, all the flaps , all the fans, all the fuses and all motors and all of the relays.
The only abnormality I can find is that the relay for the evaperator blower is HOT. So I replaced it and the new one is HOT as well. So I feel that something is wrong there. But the evaperator fan is working well at all speeds.

[echecsqueen]

So specifically
Yes I pulled the floor board and the intake is open and getting free flow of air
The air flow is great. The temps are the problem.
The condenser is not cutting off. It is working and has been. My system is an ‘88 so I do not have hi low cut off switch
I don’t have a compressor fan. The front condenser fan is working. There is not a rear condenser fan

I was scared to put more Freon in the system because the hose blew off when I was filling it before and Charlie Griffith said my pressures must have been sky high to do that to his hose
My gauge said I was in the safe range for low side pressure when it happened.

[echecsqueen]

When my mechanic put the Freon in he said he stopped because the high side went to 250. This was with the deck lid closed , running at high speed coolest temps. I didn’t have a fan blowing thru the deck though. I took the picture of the pressures right before he removed the gauge. The idle speed was around 1000

[echecsqueen]

So with the crazy hot relay and no cooling I don’t want to replace the evaporator and condenser and ruin them if the problem is something else like a blocked hose. So that is where I am.

[JRSIII]

Out of curiosity, when you are running the system, are you getting any condensation dripping onto the floor out of the smugglers box?

[echecsqueen]

No. No condensate dripping out of box

[echecsqueen]

Ordered a new set of gauges (was borrowing) and a box fan for the garage. I have been needing one to cool the engine anyway when I want to do work and it is hot

[JRSIII]

Ok that’s good info. No condensate would tell me what you probably already know…your evaporator is not getting cold. At all. With the humidity in NOLA, it should be pouring buckets if there was any temperature delta. Now I guess you need to find out why it’s not getting cold. It seems to be pointing to a Freon circulation issue, maybe a blockage. Perhaps replacing the evaporator and expansion valve will help after all.

On another note, have you measured the amps to your evaporator blower fan motor and discussed with Charlie? I’d be concerned about that hot relay.

Finally, I agree with Walt’s suggestion above. You might get more responses from folks who are more knowledgeable about this if you started a new thread with a title like “88 A/C not working”, as this thread is getting quite long.

Best of luck,
John

[PeteKz]

Ditto John's comments about condensate in NOLA humidity, and starting a new thread with the essentials about the AC problem.

Maybe you answered this, but in a quick scan I didn't see it--did this problem just crop up? Was the AC working fine last year, and this summer it isn't? If so, I'm thinking the expansion valve is blocked or stuck. Is the receiver/drier new? Whatever the cause, I think you will have to evacuate the system (again) and remove the valve to see if there's any contamination. If there is, that points to bigger problems, such as lines decaying internally. or the receiver drier blocked or some of the desiccant getting out, or the compressor eating itself. Did you replace ALL the lines with Griffiths? If so, then it's probably not the lines. Then we are back to suspecting the receiver/drier and or expansion valve.

[walt]

Someone earlier suggested adding more refrigerant. Both of your pressures are low which might indicate lack of charge, I would try this before tearing into the system. Keep the decklid closed and keep the can upright in lukewarm water to speed thing up. Hopefully you pulled a good vacuum for at least an hour before your initial charge. If that low side pressure doesn't increase to around 40 psi you may have possible contamination or faulty expansion valve.

[echecsqueen]

Sounds like a good intermediate move. We did pull a long vacuum before prior fill. I ordered a box fan and will try to set it up for optimal charging (lid shut, fan pushing air into condenser, higher rpm’s etc. the new gauges and fan should be here tomorrow so I will report back. Thanks so much guys.

[echecsqueen]

Pete kz
Yes the problem just started last month
All the hoses are from Griffith and only 2 years old.
I have an expansion valve, evaporator and front condenser on order from Griffith along with a new dryer. . But I want to make sure I don’t ruin these new parts putting them into a system with a big”other” problem.

[PeteKz]

I think ordering a new condenser and evaporator are overkill. Those components fail by leaking. You haven't indicated that there are any leaks so I'd cancel that part of the order. While it won't hurt to recheck the charge, I would expect the shop doing that work to have measured the amount of refrigerant they installed, so you should not be low. Unless you have a leak.

If that doesn't work, then check/replace the expansion valve first, then the receiver/dryer.