1987 190E 2.3 79,000 miles. Recently had some work done on this car and when talking to the mechanic he said I should leave the A/C switch engaged all the time and leave the desired temperature and the CCS would take care of the rest. Usually unless its really hot I don't use A/C. I like to have the windows and moonroof open. SO it seems pointless to me to have the A/C? Engaged. he maintains the cars were meant to operate in such a way? What should I do? Leave it on all the time? I am also having problems with the Aux fans not engaging and have been reading tons about it on this board...Am I correct that they shoyuld still engage if the A/C is off, if the Engine reaches the preoper Temp.?, ugh I just wish they would engage, thanks...

You are correct: You do not have to leave the AC settings on all the time. It is a good idea to of course run it at least once a week or so to keep the compressor seals lubed etc.

If what he said were true, you would not be able to enjoy a setting that excludes the AC!

On our '87 I found the temp sensor most forward, on top of the engine was failing. In the process of replacement I noticed a temperature rating on both the failed original and the replacement. The original had I believe a 104 C rating and the replacement (which I don't believe is a correct one) has 107 C rating.

You may want to check this sensor.

.... and hey, enjoy your sunroof, the breeze blowing through the windows!

Haasman

__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)

The aux fans are there to prevent excessive high side pressure. On many cars they are not turned on except by the high pressure a/c switch. With a/c off they very well may not come on at all. This is normal.

The reason your tech is telling you this is that with the ACC on all the time, it occasionally kicks in the a/c compressor. By occasionally turning it on, the compressor seal is lubricated preventing an eventual leak. You can accomplish the same thing by turning it on once a week.

Good luck,

On the '87 300e I purchased last year, the PO did an r124 a/c conversion & had the aux fan switch jumped so the fans were on all the time from the moment the car started. I felt that was wrong, and it was incredibly noisy, so I disconnected the wires. Car runs fine, altho the a/c doesn't seem to work. Did I do something wrong? Thanks.