air conditioning compresser


Mr.Charger

GT Owner
Dec 11, 2019
43
Germany, Hamburg
Btw : Best and most exciting car I ever had, will definitely be a lifetime keeper :cool:
Could it be the pressure switch mentioned above not turning zhe compressor on and how can we heck the switch ? Maybe that one is broken ?
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,281
Now the service point in england tells them to change the compressor. Not in stock in Germany and delivery from USA via England will take several weeks. I told them I will try to get one from US directly. Any advice where to get ? Or what to check beside the compressor?
Not a very good shop, in my opinion. "Hey, let's try replacing things and see if that fixes the problem!" Stupid.
What diagnosis did they do to determine the compressor is bad??? Two ways for the compressor to be bad.
1. Compressor is locked-up internally and won't turn over. The symptom of this is that the AC Clutch activates - and it either screams like hell or the belt screams like hell. This would be a bad, locked-up compressor - and in my experience, very unlikely.
2. Compressor and clutch are working - compressor is spinning but nothing is happening. Could be a bad compressor, but this is even more unlikely.

The AC system on the GT is NOT unique in any way. It has the same components and fail-safes as virtually any other automotive AC system. Take it to someone who can tell you WHY they think the compressor is bad... not just guessing at your expense of both money and time.

Most likely scenario is that the system is very low on charge. Spend $40 and try adding R32.

1. Start car and turn fan on high, temp control all the way to cold and AC switch on
2. Start adding charge to low side - just like any other car (ports are on passenger side, under bonnet nearer to windshield).
3. As the charge is added (cans get cold), you should hear the AC clutch cycle on - signaling that a minimum pressure has been achieved. It may cycle on and off frequently until more charge is added.
4. Use temp gauge and get vent temp at or below 40F.

All of this should be done by someone with some experience in AC systems. You'll wan to take precaution NOT to overcharge system.

If the system is taking the charge but not getting cooler, check at the compressor to see if you see any leaks where the line attach. Failures are rare, but we have seen the o-rings fail. Let me go get you a picture.... give me a few minutes.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,281
GTAC.jpg

This is a pic of how the lines are connected to the AC Compressor. If the compressor develops a leak it is typically under this block. There is an o-ring under each side. If it is leaking here, evacuate the system and then replace to two o-rings.
 

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,469
Kalama, Free part of WA State
Ditto what nota4re said.

Mr. Charger: how does the shop know the A/C system is fully charged? Did they remove, measure, and reinstall the refrigerant? A simple pressure test, when the compressor is not running, will not tell you if it has the correct amount of refrigerant.
if you can’t get another shop to check the A/C, then I suggest you add one can (about .3 Kg) and see if it starts working. Then it’s possible to measure operating pressures to determine whether the system has sufficient refrigerant.

The shop manual for the GT has a detailed system description and procedure for troubleshooting. Follow it.
 

68Rcodeman

GT Owner
Mark II Lifetime
Apr 5, 2008
811
Spring Hill, FL.
Just a thought. Wasn't there a problem with the blend door sticking and not changing from AC to heat or vise versa? I had the blend door stick on AC and no heat. If the unit was turned off in heat mode in the winter and then started and used in the summer the low side line would be cold outside and warm air would be coming from the ducts. Just a thought on a car with very low miles. Good luck.
 

Mr.Charger

GT Owner
Dec 11, 2019
43
Germany, Hamburg
First of all tsk to you guys for the helping words at all.

@nota4re I got more details from the dealers technician today, salesman informed me yesterday evening with short words. BTW its a friend company and the purple normally know what they do, the are the Europe service for all the NFGT and are in the FGT business from first day on.
They checked everything like you suggested, completely refilled the AC and does not work. As the technician will go on holiday for the next for weeks tomorrow and I need the car for a rally in 2 weeks we did not open up everything today. He would normally now first look for some electrical issue, maybe bad cables and the the compressor as well, said maybe the clutch is stuck (if I got him right ?)

So we do all this later this year with the next service, most important was to have the actual airbag recall done for safety reasons.

Maybe I would order a compressor just in case of and to have one as I will keep the car lifetime (hopefully long :)) and someone sometimes might need one. Difficult to get here in Germany, and through England with all this BREXIT thing loooong delivery times. UPS from US much faster.

@68codeman where or what is that blend door, can I check this by myself somehow ? I will pick up the car monday from the dealership. Or maybe we can check it there before I leave ? Easy to check or must many parts be taken out ?

Thanks in advance, good to have so many GT lovers around here in this very helpful forum.
Holger

BTW : If compressor needed, ask Vintage Air for a new one or any other good advice ?
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,281
Send me an email and we can send you a compressor... but I still doubt that it is your problem. kpond@sbcglobal.net
 
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HighHP

GT Owner
Jun 3, 2019
469
Spokane, WA
A very common problem is an overcharge condition. This will actually cause warm air to blow out of the registers. My 2005 GT takes only 18 oz of R134A (see refrigerant tag in front hood area). I have found that if the system is charged at idle to the high end of the pressure tables included with a gauge set or commonly stated on-line, this can result in an overcharge. Most dealers have a machine that pumps out all the freon then adds in the correct measured amount. I assume your dealer used the machine? Also, if the compressor is turning and producing high and low pressures, then it is working.
FYI - yesterday, a car buddy of mine had his compressor belt squeal when he turned on the AC. Turns out someone over filled the system so much that it slugged or hydraulic-ed the compressor. He removed some freon and the compressor turned, but no cold air, but the pressures were in the high table ranges. He continued to remove freon to the low end or below of the table ranges and now it blows cold air. Lukily, his compressor apparently, did not sustain damage. This was on a 32 custom Ford with I believe the VIntage Air system.
 

68Rcodeman

GT Owner
Mark II Lifetime
Apr 5, 2008
811
Spring Hill, FL.
@68codeman where or what is that blend door, can I check this by myself somehow ? I will pick up the car monday from the dealership. Or maybe we can check it there before I leave ? Easy to check or must many parts be taken out ?
The blend door is behind the dash inside the AC Plenum case. It is moved with a motor when the temperature is commanded hot or cold. If the shop was competent they would be able to read the high and low side pressures and know if the mechanical AC , Compressor side of the system was working properly. On the blend door it is a door that blocks the heater core which is a small radiator with hot water flowing through it and when commanding heat the door moves and blocks the evaporator core that is ice cold and the fan blows air through the heater core providing heat out of the ducts.
 

Mr.Charger

GT Owner
Dec 11, 2019
43
Germany, Hamburg
Okay I will keep all this in mind and talk to the mechanic when he is back from holiday. I will pick the car up on monday as I need it now nd we will check later. maybe I have a dealer here near by to check about the high/low pressure thing.

@nota4re thank you I will contact you if we find out the the compressor is the problem. Question would be if it makes sense to have one in spare if I keep the car for the next 20 years, maybe it will not be available later when really needed. I bet if I have one will never need it :)

Will let you know how this will go on and play a bit with the AC while driving, maybe it just has to be used a while to come back to life
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,281
Nah, I don't think it's worthwhile to have a spare compressor around.
 
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roketman

GT Owner
Mark IV Lifetime
Oct 24, 2005
8,086
ma.
Nota4re is giving you some good advice
 

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,469
Kalama, Free part of WA State
No need a spare compressor. If you have it, you won’t need it! 😁

My car has almost 70K miles (110,000km) and the AC works fine. To my knowledge, it has never needed refrigerant added, at least not in the last 8 years that I’ve owned it. But I use it frequently so that keeps everything internally lubricated. One more reason to use your car frequently!

If I understand your original post correctly, your compressor is not running. If that is true, then don’t worry about the blend door. Make sure the compressor is working first.
 

daytrayd

GT Owner
Mark II Lifetime
Apr 23, 2010
557
Austin, TX
FYI, I bought my car with a leaking compressor due to lack of use. The compressor is same as f150, we ordered that part for half the cost at the time and viola. Wish I had the part number to be of more help.
 

Mr.Charger

GT Owner
Dec 11, 2019
43
Germany, Hamburg
FYI, I bought my car with a leaking compressor due to lack of use. The compressor is same as f150, we ordered that part for half the cost at the time and viola. Wish I had the part number to be of more help.
Hi again,
summer seasons coming up and still have the GT sitting in the Garage with the AC to be fixed. You said the F150 Compressor fits, any special build year ? That we can try ? I will have the shop check the system in April again :)
thank you so much and hope all well
holger
 

daytrayd

GT Owner
Mark II Lifetime
Apr 23, 2010
557
Austin, TX
Honestly, I dont recall the part number, its been nearly 10 years, KC at Colvin automotive knew the part to order, hes a bit of a GT specialist in Texas, owns one himself. Give them a buzz??
 

Art138

GT Owner
Mark II Lifetime
Jan 4, 2011
631
Weston,FL
Believe this is it for 200 plus change: on EBay

B68F8EA2-55F1-4698-B7FB-BD6BD0A34FD6.jpeg
 

Mr.Charger

GT Owner
Dec 11, 2019
43
Germany, Hamburg
Thank you for this info. My car is going to the dealer next week they will check the system again and check if the compressor has power and is working. and will of course check the pressure of the system and everything.

Notar4re gave this hint :
I would NOT trust the Ford dealer. PLEASE do yourself a favor and get another opinion. It is RARE that a compressor would fail. ALL compressors have safeguards to protect themselves - chief among them is a pressure switch. If there's not enough refrigerant, the compressor will not even cycle on. I'd bet money that your compressor is fine.
(END)

Maybe this switch might be broken and so compressor doesn't start ? is the switch part of the compressor or an extra device to check separately ?

I have the full workshop book as PDF hopefully it will help them to find everything :)
has anyone an idea where maybe to get the full electric wiring diagram of the car (PDF/Download) might be helpful in the future because the car will never leave :)

Have a nice weekend everyone ...
Holger

BTW : a picture from a Norway Rally last year

View attachment ART2021 Ford GT3.jpg
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,680
Belleville, IL
The service and electrical manuals are for sale by Helm. There are a couple for sale on eBay right now. A 2006 copy is better than a 2005 which has some errors in it.
 

twobjshelbys

GT Owner
Jul 26, 2010
6,189
Las Vegas, NV
The service and electrical manuals are for sale by Helm. There are a couple for sale on eBay right now. A 2006 copy is better than a 2005 which has some errors in it.
Helm no longer stocks the Ford GT manuals. Secondary market eBay is your best bet. You should have one.

Edit: I had the CD (2006 version has corrections for 2005 so if you have a 05 get the 06 book(CD). The CD installer wants you to have the CD in the original install drive (usually "D"). However with a simple edit to a file you can copy the CD contents to the root of C.

The CD pages can be printed/saved to PDF for shop reference.
 
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