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  • SN95 4.6L Mustang Tech

A/C Problems.....

  • Thread starter Thread starter Jacob_Royer
  • Start date Start date Apr 18, 2008

Jacob_Royer

Member
Nov 24, 2007
142
1
19
Apr 18, 2008
#1
  • Apr 18, 2008
  • #1
Ok when i bought the mustang the a/c didnt work but it was cold outside... Yesterday i added 2 cans of pre-mixed 134a (refridgerant+oil) and it worked GREAT! ice cold!! Well today i get in and no a/c... pressure is still in the blue on my cheapo guage but the compressor is not kicking in! what now?? i tried to add a hair more freon and it didnt do anything at all... Compressor clutch??
 

Jacob_Royer

Member
Nov 24, 2007
142
1
19
Apr 19, 2008
#2
  • Apr 19, 2008
  • #2
BTW the compressor spins freely and so does the clutch.. Is there possibly a fuse or relay somwhere that could have gone south?
 

Spro

New Member
Nov 3, 2007
73
0
0
IL
Apr 19, 2008
#3
  • Apr 19, 2008
  • #3
It is possible that it is not turning on due to low or high pressure in the system. You wont get an accurate reading on the guage with the compressor not running. Now, before you added the refrigerant how much did you have left in the system before you added any? Im thinking you have a pretty good leak which brought the pressure down low enough where the compressor wont start. I checked mine while it was off in my garage at 65 degrees and my guage showed 60 psi. Heres a pic of the guage that I have. Hope this helps out.

 

Jacob_Royer

Member
Nov 24, 2007
142
1
19
Apr 20, 2008
#4
  • Apr 20, 2008
  • #4
I was right at 25 when i charged it enough to work.. sat over night after running all day, then next day NOTHING! argh!! So i think maybe i have a leak?? maybe i didnt have enough in there anyway? so i add a little more.. and the compressor wont ever kick on! now its sitting on 32 with the compressor not kicking on at all.
 

COramprat

...I can take it. I think.
20+ Year Stangneter
Mar 2, 2003
8,474
1,463
223
Sea of Tranquility
Apr 20, 2008
#5
  • Apr 20, 2008
  • #5
If the pressure is good then it could be the clutch...I can't remember how to check it though.

For the clutch replacement do a search for compressor clutch under my screen name. I replaced mine a few years back.
 
W

Will Smith

New Member
Aug 8, 2004
191
0
0
Cape Coral, FL
Apr 20, 2008
#6
  • Apr 20, 2008
  • #6
Spro said:
It is possible that it is not turning on due to low or high pressure in the system. You wont get an accurate reading on the guage with the compressor not running. Now, before you added the refrigerant how much did you have left in the system before you added any? Im thinking you have a pretty good leak which brought the pressure down low enough where the compressor wont start. I checked mine while it was off in my garage at 65 degrees and my guage showed 60 psi. Heres a pic of the guage that I have. Hope this helps out.

Click to expand...

if when u checked your gauge when the vehicle was off and it read 60psi then u have a leak somewhere in the system. When an a/c system is turned off the high and low sides will equalize out... normally its around 80-100psi. when the vehicle runs the low side drops to about 32-35 on the low side and around 200 on the high. what i do recommend is either take your car to a good a/c shop/or dealership. or invest in a a/c Dye light and A/c glasses. if you do the later make sure to check all lines and connections for leaks. You may want to remove the front 8mm bolt on the compressor and pull the clutch plate out to see if you have dye on it and check the Evaporator case drain for signs of dye.
 

blackink00

I missed a shift & stole Curt's money.
Mar 30, 2005
545
0
0
Tempe, AZ
Apr 20, 2008
#7
  • Apr 20, 2008
  • #7
the compressor wont kick on with a static pressure under like 40psi. but most likely you have a leak. take it into a shop and have them diagnos it. unless you have the proper equipment and know what your doing you shouldnt work on your ac system. they are very sensitive to how much refridgerent you add and moisture and all that stuff. just take it in.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,365
18,109
224
Massachusetts
Apr 20, 2008
#8
  • Apr 20, 2008
  • #8
More than likely a leak somewhere
 

the98stang

Active Member
Aug 12, 2005
2,408
0
47
Clovis, CA
Apr 21, 2008
#9
  • Apr 21, 2008
  • #9
If the compressor is not kicking on, it might be your cycle switch. Remove the cycle switch (passenger firewall area) and short it with a paper clip for a few seconds. If the compressor kicks on, your switch it bad. Replace the switch and all should be fine.
 
W

Will Smith

New Member
Aug 8, 2004
191
0
0
Cape Coral, FL
Apr 21, 2008
#10
  • Apr 21, 2008
  • #10
the pressures dont indicate a short in a switch... i would recommend starting with the leak in the system since it will be the large $$ amount here... get that resolved and then if u still have problem then go to your electronics...
 

the98stang

Active Member
Aug 12, 2005
2,408
0
47
Clovis, CA
Apr 22, 2008
#11
  • Apr 22, 2008
  • #11
Will Smith said:
the pressures dont indicate a short in a switch... i would recommend starting with the leak in the system since it will be the large $$ amount here... get that resolved and then if u still have problem then go to your electronics...
Click to expand...

Why would you try to fix the most expensive part first? A new switch is like $10 from the dealer anyway. And testing the switch is FREE. It's not uncommon for the cycle switches to fail on these cars as well. I'm telling you if the compressor is not kicking on it's worth 5 minutes of your time to short the switch to see if it's the issue.
 
W

Will Smith

New Member
Aug 8, 2004
191
0
0
Cape Coral, FL
Apr 22, 2008
#12
  • Apr 22, 2008
  • #12
the98stang said:
Why would you try to fix the most expensive part first? A new switch is like $10 from the dealer anyway. And testing the switch is FREE. It's not uncommon for the cycle switches to fail on these cars as well. I'm telling you if the compressor is not kicking on it's worth 5 minutes of your time to short the switch to see if it's the issue.
Click to expand...

due to the low, low side reading that he posted a picture up of the system has a leak...there is no doubt bout it....the reading should be atleast 80-100 or so with the vehicle's a/c not running...im very familiar with these vehicle since i do work as a tech at a ford dealer... the problem he has first is a leak in the system... the system will need to be charge and sealed before other diag on electrical systems are checked...
 

the98stang

Active Member
Aug 12, 2005
2,408
0
47
Clovis, CA
Apr 22, 2008
#13
  • Apr 22, 2008
  • #13
Will Smith said:
due to the low, low side reading that he posted a picture up of the system has a leak...there is no doubt bout it....the reading should be atleast 80-100 or so with the vehicle's a/c not running...im very familiar with these vehicle since i do work as a tech at a ford dealer... the problem he has first is a leak in the system... the system will need to be charge and sealed before other diag on electrical systems are checked...
Click to expand...

Sorry I didn't realize that picture posted was of his exact pressure reading...
 
W

Will Smith

New Member
Aug 8, 2004
191
0
0
Cape Coral, FL
Apr 23, 2008
#14
  • Apr 23, 2008
  • #14
the static pressure on the low side needs to be atleast 60 or so for it to even kick on...and with the vehicle off that low side should go to atleast 80-90 or so....
 
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