w140 A/C problems- 1994 S320 - PeachParts Mercedes-Benz Forum

1994C220 · #1 01-06-2003, 10:25 AM

Hi...well, I finally got the blower regulator changed out...and my heater is working great now...but, my AC is completely shot. The climate control only works in EC mode. I ran the diagnostic tests from K6JRF's page...and This is what I got for error codes:

EO 13 and EO 91

According to the site EO 13 is the connection to rear climate control module.

and EO 91 is the A/C compressor ground activation. When I clear out the codes and try to turn on the AC...the compressor clicks on for about a second, and there is a horrible screeching noise that comes from the belts around it...and then I guess it disengages itself and i get the EO 91 code again. The AC will stay in regular mode, but you can tell that the compressor is not turning on...until you clear the code, and the same thing happens again.

What I would like to know is how do I fix both of these problems? Or what do I need to check? Please give me specifics as possible, I am not to mechanically inclined, but with the right help, I have already been able to do the blower regulator in this car and I replaced the window switch console in my wifes ML yesterday.

I ran operational check too...Here are the #'s and values:
1-85, 2-72, 3-98, 4-87, 5-76, 6-99, 7-2, 8-18, 9-30, 16-0

Thanks in advance for your help...

savagetom · #2 01-06-2003, 11:36 AM

Sounds like your compressor is seized. You'll have to replace it.

JimF · #3 01-06-2003, 11:37 AM

From what you said, it appears that the compressor is seized! If that's the only thing wrong, no big deal. So good luck!

1994C220 · #4 01-07-2003, 09:14 AM

Ok, hopefully it is just the compressor. Is this expensive? I know that I saw it listed on a dealer site somewhere for 800.00, but Im sure its available through fastlane cheaper...the blower regulator I just bought and replaced lists at the dealer for almost 400..but I found it for 135.00.

Another question is, can i do this job myself? or is it too tricky to risk messing up other components? And if it is too time consuming, can a good independent shop do it? How many hours of labor would it cost?

Thanks for the help

JimF · #5 01-07-2003, 11:38 AM

that's the only thing wrong, which is a bad assumption, then you still need to evacute the complete system to ensure it's clean and dry before you refill it!

I said it's a bad assumption because there are probably many other components bad. The receiver-dryer is most likely bad too.

So bottom line, as many other more qualified people on the site have recommended, have it done by a indy shop.

BTW, do a search to uncover some good A/C tips.

1994C220 · #6 01-07-2003, 05:26 PM

thanks...I guess Ill have to start saving up some money before the TX summer hits...

Other than the AC, and a terrible driver's side seatbelt problem, however...I have been extremely happy with my S class....

JimF · #7 05-24-2003, 02:17 AM

happened to my a/c compressor but for a different reason.

Read this thread if you haven't already: http://www.peachparts.com/shopforum/showthread.php?threadid=65697

It seized also: would start for a second, then stop. Initially thought it was the clutch but no such luck. Did most of the 'work' myself so that kept the cost down but once it seizes, you need to flush and replace major components.