If the pressure sensor is disconected, and there is stil no voltage, than it can be wiring problem, including switch, computer and loose connections. One needs wiring diagram to evaluate possible problematic spot.
On the line right at the compressor.
the low side pressure port is located just off the back of the compressor, the highside is located in the line on the side of the compressor body
The 2001 Saturn L200 low pressure port can be found on the air conditioning compressor. The low pressure port will be closest to the front of the engine compartment.
Low pressure line from the compressor (Larger hose)
You should be able to find two ports, may have a red and blue, or both black but two diffrent sizes, generaly high pressure is by the compressor, and low pressure is bt the condencer (by the radiator)the bigger of the two is low pressure, the smaller of the two is high pressure.
Low or no refrigerant Blown Fuse Defective pressure switch Bad clutch on compressor Selector switch
Larger hose from a/c compressor may be near the drier on the passenger side firewall
A reciprocating compressor is one in which a piston or diaphragm moves in a reciprocating motion. The compressor used in the AC system of a Saturn is NOT a reciprocating compressor. It is most likely a "rotary vane" compressor.
More than likely it is low on refrigerant and the compressor is kicking off on the low pressure switch. After it is off for a few seconds the low pressure switch resets and starts up again, runs a few seconds and off again. Continuous cycle of off and on.
The AC compressor on a Saturn (S-Series) is pretty much the highest device that is driven by the serpentine belt. It's on the passenger side, near the front of the engine compartment. There are two large pressure hoses that are attached to it.
If you want it constantly running jumper the high pressure cut off switch wire. And if you dont want it running turn off the ac. If pully is seized see if a napa can get a shorter belt to route around the ac compressor
when the defroster is turned on, it activates the a/c compressor. the clutch may be locking up on the compressor.