Question about 1993 Saab 900

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94 Saab 90 SE AC blows hot air

I've discovered that the AC clutch doesn't engage. I have voltage to the compressor. The low pressure switch shows no continuity. AC coolant temperature switch shows continuity. I haven't been able to locate the anti-frossting switch to check it.

How can I tell whether the clutch or compressor is bad, or the R-12 charge is low? I suppose I could have the R-12 charge checked. Am I missing something.

Thanx

Bill

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Hi Bill
Usually the clutch is frozen means you need Freon R-12, please go to the small glass window on the condenser to find out there is some white bubbling inside, if you have white bubbling means your AC lack Freon, but if you lost all Freon, the window is clear, so you have to check, I hope from there, you can tell the Freon level.

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1 Answer

Air conditioning


It doesn't sound like you have low Freon, but you could. The clutch not engaging indicates low Freon. The fact that it works are all would indicate that it is not low on Freon. The only thing that would be wrong is the pressure switch is not working when it gets hot. The pressure switch works by shorting the float side connection to ground then there is enough pressure in the system.

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I have a 2001 Ford Mustang V6, the ac is blowing warm air. We checked the refrigerant and it is full. The ac compressor will kick on for a few seconds and then kick off. Why is the compressor not staying...


it's either low (in spite of your readings) or your a/c clutch is not working correctly or you have too big an air gap in the clutch.
First, just disconnect the 2 pin connector from the a/c pressure cycling swithc and jumper the 2 pins with a wire to force the clutch to stay engaged. See if it blows cold then, and stays engaged. You can run this way for about 15 minutes before you have to pull the plug.
report reulsts.

please don't forget to rate.

Sep 01, 2011 | 2001 Ford Mustang

1 Answer

Compressor isnt turning at all dont know if i need new one or if i need new clutch how can i tell


The pulley on the compressor is always running when your engine is running, but the only time
it compresses the freon is when the clutch engages, if the compressor's pulley was not turning,
it would have already snapped a fan belt or your serpentine belt. voltage runs from your fuse box
thru your air condition switch on your dashboard to a low pressure switch that is located at the
accumulator a long cylinder,close to the firewall under the hood or close to the condensor, front
of the car. the switch detects freon pressure in the accumulator, if there is freon pressure, the switch
will stay closed and allow voltage to go to the compressor clutch to engage it and compress the freon,
if there is no freon pressure the switch will open, and there will be no voltage to air compressor, its a
saftey switch to keep your compressor from getting damaged.its possible that the switch could be bad
it may not have voltage at the switch, or it may be open because there is insufficient freon pressure.
check and make sure there is freon in the system.check for voltage at the low pressure switch if you have freon in your system and voltage at the pressure switch, set your ac on high, pull the molex off
the switch, and jump it out with a jumper wire, if the clutch engages and your car starts to cool, just
replace the switch. if the clutch engages but does not cool, then your ac system has some blockage
in the lines. if the clutch does not engage at all then it would be the compressor clutch. good luck!

Aug 03, 2011 | Buick Century Cars & Trucks

1 Answer

Everything on ac has been replaced and its still blowing hot air. It seems to be some kind of electrical problem because the compressor is not engaging most of the time. when it does it blows very cold air


The accumulator a long cylinder depending on the car may be located close to the fire wall under the
hood or close to your condensor. it will have a pressure switch, called a low pressure switch senses
freon pressure in the accumulator, if it is not getting voltage to it or there is a leak on its seal, it will open
up and will not let voltage go to the clutch on your ac compressor. you can pull off the switch, turn on your ac on high, get a paper clip or jumper wire, and jump the molex if your compressor comes on and
your car starts to cool,check the switch it may not be seated all the way, its a normally closed switch,
if you read across the switch with an ohm meter you should get a closed loop,when the ac is turned off,
you can remove it to test it without pulling the freon. if its open the clutch will not work, also check the
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Location of ac high pressure cutout switch on a 97 Plymouth voyager. Could it be a different problem? Had to replaced the PCM and a couple sensors because of a short in the wiring cluster. Now the ac...


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1 Answer

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Find the AC compressor. The pulley on it has an electric clutch that allows the compressor to run when the AC is on and not when it is off. With the engine running you should be able to see if the clutch is turning or not. The pulley turns all the time the engine is running only the clutch behind the pulley starts and stops. Look at the pulley with the AC off. Have someone turn it on and see if the clutch engages to turn the compressor. If it doesn't engage there are a couple thing that could be wrong. First the clutch has burned out and no longer works. The fuse on the AC clutch is blown. Check the fuse. More likely, if the cold air has been getting warmer, the AC system has a refrigerant leak. The system has a low pressure switch that prevents the clutch from engaging when the refrigerant pressure is too low. If the fuse is good then you need to have a qualified AC Technician check the system.

Thanks for using FixYa.
Gaker

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1 Answer

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1 Answer

My 2002 Expedition air conditioner will sometimes blow hot air and others cold air


I would check the following possibilities:
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Good luck

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1 Answer

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1 Answer

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