1988 190E 2.3 A/C Works Intermittently - Benzworld.org

Guest (MBNZ) · 09-09-2001, 05:36 PM

My A/C has been working great for the past year, blowing ice-cold, but after the car sat unused for several weeks, I now have an intermittent pblm with A/C. There seems to be a short, or fuse, or switch failure that occassionally turns on the compressor -- other times it won't. I checked the fuse and discovered previous owner had cracked open the fuse box cover, which I suspect has been allowing some rain to drip into the fuse box. Fuse was okay. I don't think its a vacuum problem with A/C damper because I can hear the compressor kick in whenever the a/c is about to blow cold air and work again. The absence of compressor sounds makes me wonder about electrical problems. Any suggestions on how to check electrical stuff more thoroughly -- any other fuses or relays that might be cause of trouble? Any simple way to remove the a/c elec. line from the fuse box on the hunch that the fuse connectors (socket) might be corroded a little? 
thx, 
marty

Guest (MBNZ) · 09-10-2001, 03:19 AM

it's a stupid suggestion, but did you check your freon pressure?

Guest (MBNZ) · 09-10-2001, 09:38 AM

No, I didn't check the freon pressure, but would low pressure account for the compressor not even kicking on (other than when it has a mind to)? When the a/c decides to work, it works fine for awhile. Sometimes, it will quit blowing cold for a few minutes and I don't hear the compressor cycling on/off as 'normal'. Then, it might just mysteriously start cycling on/off again after several minutes and cooling off just fine. The one symptom that makes me think that there may be further justification for checking the pressure, though, is that the a/c (in 100+ temperatures lately) doesn't seem to blow as cold as it did a few months ago. I've attributed it to excessive heat/humidity because at night the a/c will freeze you out of the car. Maybe I should have it checked, though. marty

Guest (MBNZ) · 09-11-2001, 03:04 AM

believe it, or not, but my wife's '96 Mustang did the same thing, and actually she lost all the coolant. Of course, the diagnosis was bad compressor (or the internal seal). The compressor has a pressure switch, and when the freon (or coolant)is too low, the compressor will not kick in until the pressure builds up. I don't thing the outside air temp has anything to do with it (it was my wife's excuse. unfortunately,it could be your compressor (that's my problem). the remanned one will run you $600, or, if you look around, it could be as low as $280. Of course, you'll need receiver/dryer (another $75). Remember,that 190's were never designed to have AC. The AC system was thrown in for US market.

Guest (MBNZ) · 09-18-2001, 08:49 PM

Beleive it or not(again?) I' ve got my 1986 2.3-16S for 6y now, and I' ve got exactely the same pb... The a/c stops running sometimes in the middle of a course and I just have to stop the car and re-start and everything is fine for the rest of my trip. I' m gonna change my compressor though. Any of you know where I can PARTS for it on the web nowadays? not just the compressor I mean... Thanks Hei

Guest (MBNZ) · 09-21-2001, 05:28 PM

try thebenzbin.com that's the only place I shop

Guest (MBNZ) · 03-17-2002, 02:01 PM

Hey everyone, I have a 1987 16V Euro. I had the same problem with my a/c for 5 years till my brother finally stumbled on the answer. The compressor has a fail safe. It takes a engine reading and if it thinks the engine is off or if your belt is sliping it will shut it down. The problem ended up being a loose connection. There is a 3 prong plug on mine near the back of the compressor on the left side (wheel side). I just took the conector apart and squeezed the prongs together a little to give a better connection. The a/c has not stopped once. I had replaced a perfectly good a/c control unit and numerous other components which were probably all good. Oh well. Live and learn.