97 C230 A/C Issues
 

The A/C in my 1997 C230 is not working. It seems as though the compressor is not running.

I've looked through most of the archives on this type of issue and would like a little confirmation of my findings.

1. Actual value #7 (refrigerant pressure) reads 00*6, which I take to read 0.6 bar. Is this low enough to fail the pressure switch?

I tried to short the pressure switch, but I'm not sure I did it correctly. I pulled one of the plugs at the receiver/drier (it has 2 wires coming out of it, there was another with 3 or 4 wires I assumed was the temp switch). I shorted the 2 wires, but nothing really happened. Incidentally, the voltage between the two wires was 5 VDC no matter what the climate control system was set on.

2. I took a voltage reading from the plug to the compressor (one wire) and ground. It read about 160 mVDC when the "EC" mode was on (i.e. no AC) and about 180 mVDC after I toggled the EC button.

3. The belt is fine around the compressor, nice and tight, no sticking or flopping.

Any ideas? My thinking right now is that the pressure is too low. I'd like to try to test the compressor though to make sure it is OK. I've also read that you may have to put 12v to the low pressure switch to engage the clutch rather than shorting the wires. ???

Thanks to those who read this!

I looked at a few more things, these are actual values and error codes.

Actual Values:

1) 104
2) 89
3) 110
5) 109
6) 195
7) 00*6
8) 96 F
9) 50 F
10) 520
20) 00
21) 080
22) 000
23) 000
40) 01
41) 03
42) 18
43) 6-C
50) 111
51) 72 F
52) 50 F
54) OFF

Errors

419, 421

Int Errors

23*2, 23*3, 41*6, 42*2, 45*9, 45*1, 45*3, 45*4, 45*7, 45*8

I deleted the Intermittant codes by hitting the ^ and v buttons together.

I have also noticed that the radiator fan does not run, it is quite hot here in southern Arkansas, around 100F. I figured it should be running, but not sure.

Thanks for the help.

One last thing. . .

I was looking around more, and I think the low pressure switch was the one with 3 wires. In that case, the voltage from the ground pin to the center was 5 VDC and from ground to the outer pin was 9.9 VDC. Shorting the two non-ground plugs didn't do anything.

Thanks