Hello,
I just replaced the compressor, dryer and expansion valve on my '95 S320, (thanks to some help locating it from Sleepwalker). We thoroughly vacuumed the system after cleaning with the proper solvent, recharged to just a bit less than 2.5 pounds of R134.
The problem is that the compressor turns on for about 10 seconds and then off for 2-3 minutes, the starts over for 10 seconds, off 2-3 minutes, etc. All the pressures are within the specified range. The compressor runs good when we hot-wire it directly. I assume some sensor is not working? Any ideas?

 

read the sensor value.

 

could be an over heat switch ..did it do this before ..?or evap temp sensor

 

Thanks for the response, Sleepwalker and MB/TECHMAN. No, everything was working fine other than the screaming compressor which leaked refrigerant. And, unfortunantly, I do not know how to read the sensor value or which sensor it would be. I'm a novice at this. Any advice on this? Thanks again for your help.

 

OK, I figured out how to run the diagnostics. It says I have a EO 45 and EO 47 errors, refrigerant pressure sensor short circuit and refrigerant pressure sensor open or short circuit.
Cool! Does this mean I need to replace this sensor? Thanks!

 

you may need to do further more check about that sensor till you are convinced that it was defective.

 

sleepwaker it could have bad pressure switch on drier ...??

 

possible.

 

Replacing the pressure sensor eliminated the diagnostic errors I was originally getting. I now get no errors BUT the compressor still runs a few seconds, kicks off, starts again a few minutes....over and over. Also, when I "hot wire" the compressor to fill up and test pressures, the air blowing into the car is not cold, a drop of only a few degrees.

 

With the replaced sensors (pressure and evap temp), I now get no faults or errors, and the same intermittent running of the compressor. But, an odd thing is occurring (or I just now noticed it). When I punch the right "Auto" button while in diagnostic mode, the auxillary fan kicks on for a few seconds every time I press it. I then unplugged and jumpered the pressure sensor leads, as was suggested in the archives, and the auxillary fan does nothing. The pressure switch is new. The only way to activate the low speed fan is to ground the center pressure lead. Unplugging the temp sensor on the thermostat housing activates the hi speed aux fan as it should. It almost seems as if its a grounding problem but, with no error codes it is difficult to know where to start?

Errors or faults: none

Actual Sensor values:
1 - 97 deg in car temp sensor
2 - 95 deg outside temp sensor
3 - 100 deg left heater core temp sensor
4 - 100 deg right heater core temp sensor
5 - 98 deg evaporator temp sensor
6 - 103 deg ECT sensor
7 - 8 refrigerant pressure in bar
8 - 45 blower control voltage
9 - 30 software status
16 - 0 active charcoal filter "no"