I need a little help here with the a/c in my '99 C280 with 120k miles. The unit is not putting out cool air. First I thought it was out of R134a and when I checked it with a pressure gauge, it was reading zero. However, when I tried to put in some R134a, the pressure reached the 25-45 mark even though the can of refrigerant is still almost full!

I took the readings from the dashboard control console and these are the numbers I got with the car having being parked almost 24 hours without being started.

Engine Not Running; Key in position #1.

01 = 79F
02 = 70F
03 = 77F
05 = 122
06 = 75F
07 = 01*4
08 = 69F
09 = 50F
10 = 250
20 = 00
21 = 000
22 = 000
23 = 000
24 = 12.3
40 = 03
41 = 03
42 = 26
43 = 6-C
50 = 50F
51 = 72F
52 = 50F
54 = OFF

Engine Running, Car Was Not Driven After Sitting Parked For Almost 24 Hours. Reading Was Taken Immediately Car Was Started.

01 = 78F
02 = 70F
03 = 75F
05 = 122
06 = 125
07 = 01*4
08 = 69F
09 = 50F
10 = 260
20 = 00
21 = 000
22 = 000
23 = 000
24 = 13.8
40 = 03
41 = 03
42 = 26
43 = 6-C
50 = 75F
51 = 72F
52 = 50F
54 = OFF

From reading other similar posts here on the Forum, it appears that #05 represents my Evaporator Temp Sensor, and it appears that it is running hotter the Core Sensor which I believe is represented by #03 above. Am I correct in this analysis? And if so, what does that all mean and how do I go about fixing this problem. Also, I tried but did not get any error codes, or maybe I didn't do that part correctly?

I would like to get this reapired before the Chicago summer heat gets here and would really appreciate any help given.

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1999 C280
1995 XJ6
1989 LEGEND L
1988 MX-6 Turbo