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2000 Saturn: Air Conditioner..Compressor..the clutch to kick

Customer Question

I have a 2000 Saturn whose Air Conditioner Compressor has stopped turning. I have a licenced business/friend who can help me re-charge, but my question is this:

IS THERE A LOW PRESSURE SWITCH somewhere in the lines, that will not allow the clutch to kick-in, if the A/C charge is too low? The compressor WILL turn by hand so it is NOT frozen-up, and I DO HAVE 12-VDC at the powe wire to the clutch.

Everything else seems "Okay"
PLEASE reply A.S.A.P.

Submitted: 8 years ago.
Category: Saturn
Expert:  MPMoore replied 8 years ago.
What model and engine do you have??
Customer: replied 8 years ago.
It's a 2000 Saturn SL, LEAST expensive model made, so it is the smaller of the 4-cylinder sizes. I do not know engine number or CID, or Liter? Do you need to know this?
Expert:  MPMoore replied 8 years ago.
There is a sensor that keeps the compressor from comming on with low pressure. Here is the diagram of the system.
I am not able to find the location of this switch, but is normally on the low side lines (which are the larger size line) on the system under the hood. I did find a pressure switch that is located on the liquid line.

Object Number: 862057  Size: SH

VAC Schematic - Continued

Object Number: 875742  Size: FP

MPMoore and 2 other Saturn Specialists are ready to help you
Customer: replied 8 years ago.

Hi again,

I did some further electrical testing, and this is what I think:


Set condition tested:

With the A/C Switch "ON" and fan speed high, recirc-hot air inside car, selected on dashboard controls, after I had the engine running.


I checked for 12-VDC at the plug on top of frony of compressor. I DO HAVE 12-VDC!


The compressor clutch should pull in, with 12-VDC applied at that connector, to energize the COIL! IT DOES NOT!


Therefore I suspect the Compressor clutch 12-VDC COIL has failed! DO YOU AGREE?


Thought process: If a pressure switch was preventing the clutch-plate from pulling in, to turn the compressor shaft, there should be NO 12-VDC present at the power-in connector to the clutch-coil. Am I correct?


SO next question: Do you know if I can buy and replace JUST THE 12-VDC COIL?

OR must I replace the entire Clutch Assembly, on the front of the compressor?


Please reply A.S.A.P.! I'd like to get this finished BEFORE the REAL-HOT weather arrives!



Expert:  MPMoore replied 8 years ago.
If the clutch is getting power, then it should engage. Make sure you test the gound circuit also at the compressor. You should be able to use a test light, the light should light up. Even if you have 12 volts, it may not be a strong 12 volts. If the test light lights up, then you do have a good 12 volt source. Here is the wiring diagram for the compressor. You can replace the clutch, most people do replace the compressor. You need special tools to remove the clutch.

HVAC Schematic

Object Number: 875739  Size: FP

Customer: replied 8 years ago.

This does NOT answer my question!

1. I am unable to open, or read ANY of the diagrams, or Schematics, that you have sent me. All I get is the message:

"You are not authorized to view the requested information."


2. This Saturn only has the HOT 12-VDC wire, going to the electrical connector on top of the clutch, to feed the coil, that engages the plates so the compressor will turn. What this means is that because the compressor is bolted to the Engine block, and the Engine has a LARGE Ground strap, that connects to the battery's NEGative post. There is NO WAY there could be a bad ground. I am an electrical engineer.


3. I used a "VOM" DC-voltage Meter to read the 12-VDC, because I did not have a test light. There is no wear of the wires or bad connections, so I do not question having enough 12-V power, to engage the clutch.


4. My question was, & still is: DO YOU KNOW IF ONLY THE 12-vdc ELECTRO MAGNETIC COIL, CAN BE REPLACED, or must the entire clutch assembly be replaced? I have the PULLER-Tool(s) due to my associate having an A/C business. He just is unfamiliar with Saturns.


5. I do not believe that the Compressor is bad. Therefore I do not plan to spend the money to replace it. The LESS $ I must spend, the better.


Last Question:

Do you know of a Web-Site where I can buy Saturn Parts at wholesale, or at a discount?

I will need either a Coil-Assembly, or entire clutch & Electromagnet Assembly if that is the only way it comes.


I will pay some more money to "just-answer".com, if you can definitely clarify this, and answer my specific question(s)

Thanks for your responses! They are greatly appreciated, and I am NOT annoyed that we have not gotten to a solution to my problem yet.


We could see NO pressure switches anywhere along either the "Liquid-Line" NOR the "Suction-Return" Line(hoses) that would be considered in the engine compartment (under the hood) that is.

Please reply, even if it needs to be Monday.



Expert:  MPMoore replied 8 years ago.
Sorry about the diagrams, I have never had a issue with them before. Normally works when "view full image" is clicked on. The wiring diagram shows the ground circuit is gong to the case. You can try measuring ohms, GM does not have a spec, since the fuse is only 10 amps, should be around 10ohms. They show a thermo fuse in the diagram as part of the coil, may want to remove the clutch and check the coil and fuse. Saturn does show a proceedure for replacing the clutch coil assembly, I do not know of any supplier for the part other then the dealership.
I am sure the coil needs to be replaced, if you have 12 volts to it, then all switchs that control the hvac system is working.
If you have no amp draw at the clutch or a open circuitat the clutch, then this should be your problem.
MPMoore and 2 other Saturn Specialists are ready to help you
Customer: replied 8 years ago.

Thanks again!

Just to let you know, I went back and tried again to view & print the diagrams.

THIS time; it works when "view full image" is clicked on!


I plan to pull the clutch, and try to find that "High-Temp.-Fuse"! Do you know if it is difficult to get at, and is a replacement fuse something special from Saturn? Or could it be available at an Auto-Parts Store?


I will also check Current draw, just-in-case the clutch coil is shorted, THAT would cause the high-temp-fuse to blow! I'm not surprised really, at almost 9-years (will be in Sept) we've had this car. Never had any A/C problems before, and this clutch IS a high use item, because it runs not only when A/C is needed, but also when the windshield-defroster is on, and the "temp-knob" is not on full heat.


Thanks for your help! I will try to let you know how I make out!

Expert:  MPMoore replied 8 years ago.
I know nothing of the hi-temp fuse. At the dealersip, we dont replace the clutch or coil, but the compressor. This is due to warranty issues, there are no warrantys when replacing the clutch or coil, a lifetime warranty for the whole compressor when its replaced.

Air Conditioning Clutch Coil Replacement

Tools Required

SA9149AC-2 Puller Center
SA9149AC-3 Drive Plate and Pulley Installer

Removal Procedure

Object Number: 861528  Size: SH

Important: It is not necessary to discharge the A/C system to service the A/C compressor clutch.

  1. Remove the accessory drive belt from the compressor clutch pulley by rotating the belt tensioner clockwise using a 14 mm (9/16 in) wrench. Snap-On™ tool S8190A or equivalent can be used.
  2. Disconnect the A/C compressor clutch electrical connector.
  3. Important: The next 7 steps are only necessary if the vehicle is equipped with a secondary air pump reaction system (AIR).

  4. Remove the nuts from the combination valve studs.
  5. Remove the air hose.
  6. Remove the vacuum source hose. There is no need to disconnect the internal vacuum hose for this procedure.
  7. Remove the combination valve and gasket from the rear air compressor bracket.
  8. Position the combination valve and gasket away from the A/C compressor bracket.

  9. Object Number: 865483  Size: SH

  1. Remove the air pipe nuts from the exhaust manifold studs.
  2. Remove the air pipe.

  3. Object Number: 861409  Size: SH

  1. Remove the rear A/C compressor-to-engine bracket bolts.
  2. Remove the front A/C compressor-to-engine bracket bolts.
  3. Notice: Ensure that A/C discharge line does not change position and/or loosen at the condenser connection due to moving discharge line. Failure to ensure a tight connection will result in a system refrigerant leak.

    Object Number: 861526  Size: SH

  1. With the A/C lines still attached, lift the A/C compressor upward and install one front bolt through the front engine bracket top hole and bottom rear mounting ear of the A/C compressor. Tighten the bolt so that the A/C compressor is supported by the bracket.

  2. Object Number: 861524  Size: SH

  1. Position the screwdriver between 2 vibration dampeners on the front of the clutch face and remove the clutch bolt.

  2. Object Number: 861953  Size: SH

Important: Be careful not to lose shims inside of the clutch drive plate opening when removing the drive plate from the compressor shaft.

  1. Position the flat blade screwdriver under the clutch drive plate and pry out evenly to remove.

  2. Object Number: 861522  Size: SH

  1. Using external snap ring pliers, remove the snap ring.
  2. Notice: Do not remove pulley without puller adapter. If A/C compressor shaft is pressed on, A/C compressor will be damaged.

    Object Number: 861521  Size: SH

  1. Position the tool SA9149AC-2 on the end of the A/C compressor shaft.
  2. Important: Make sure to hook the puller jaw behind the pulley.

  3. Install the 3-jaw puller on the A/C compressor pulley. Tighten the center bolt to remove the pulley assembly.
  4. Important: To enable easier removal of the screws, lightly tap on the end of the screwdriver with a plastic hammer.

  5. Remove the 3 A/C compressor clutch coil screws and remove the A/C compressor clutch coil.

Object Number: 861518  Size: SH