TheEngineer

On my '95 E320 the climate system didn't work right. The A/C compressor would come on at times for a short time at the beginning of a drive and then it wouldn't come on any more. I traced the fault to the A/C relay, also known as the Klima relay. After I removed the relay and connected pins 5 and 7, the compressor clutch engaged and I had cold air. This was a test. A new relay costs about $135 and I thought, I'd open it up for a look-see. There are two minature relays in there, soldered to a circuit board. I removed the cover of the one relay that provides contact between pins 5 and 7. I actuated it using my finger. That must have freed the relay because now the A/C works just fine. I guess, because this relay cycles very often, and because it's so small, it gets stuck after years of operation. Any comments?

myfirstbenz

hmm, i'll have to open mine up as well. any picutres?

TheEngineer

No pics because I thought at the time that I was opening up a scrap part. I was surprised at finding a complex circuit board and what appeared to be two relays. I just opened up one relay out of curiosity. I had planed to borrow a good A/C relay from an aquaintance who has a '94 wagon. He's a Mercedes mechanic and very helpful. Those guys really know their cars! Long gone are the days when I made a car from parts from a junk yard. But you can remove the silicone sealant from the bottom of the case using a 1/8 flat blade screwdriver. Then you can spread the case a little and withdraw the circuit board assembly. The minature relay I opened is the one that connects pins 5 and 7. Just trace the connection on the circuit board. I opened the relay using small wire snips. Finger Nail cutters might work too. Be careful not to damage the relay inside. Remove just little pieces of cover at a time. I'll test the car for a while and, if it keeps on working, remove the relay and snap a pic for you. Note: This procedure is probably not aproved by MB or Bosch!

myfirstbenz

Oh my goodness , then I shall not even dare to try it