Can I put a A/C compressor from a 420SEL into a 300SEL?
 

My 1989 300SEL A/C compressor is dead (I left clutch pieces somewhere along the road - the compressor still turns, but with difficulty).

I have a '91 420SEL that I might fix when time and available parts permit (waiting for a cheap donor car with a good engine to present itself). I'm thinking of taking the compressor off of my 420 and putting it on my 300. Will this work?

I know the pulley would have to be changed (420 has v belts, and the 300 has a serpentine). That would be straight forward, right?

I also know that the 300 compressor has a speed sensor on it that the 420 doesn't. If I switch out the Klima relays also, would that get around the speed sensor issue? Or can I put the speed sensor on the 420 compressor?

Thanks for any thoughts.

-Brett

Is there a way to edit the title of posts? I'm referring, as you may have guessed, to the "a" instead of "an" in "... put a A/C compressor ...". Can we say the missing "n" is assumed?
-Brett

No go, you must have the speed sensor (or swap the KLIMA for an "ice cube" relay, a simple one and forgo the belt protection).

Also, if the compressor died, likely you need to do a very good flush and install a filter on the return line to prevent the shrapnel all over the insides of the system from promptly killing the new compressor.

Peter

No Edit For Titles
 

The only way I found to edit the title post is to delete the post and paste the text into a new post. :D

It will not phisically fit. The AC compressor size for the 300SEL is 16 while for the 420SEL is 17 and the AC clutch is different.

Don't forget what Mr. psfred mentioned about fushing.

Thanks guys.

I'll give it a good flushing.

It looks like the compressor on my old 190E 2.6 is the right size. It has the speed sensor and the right clutch too. I was just reluctant to start stripping parts off of it because it still runs (even though I don't use it anymore) and it was my first Mercedes.

-Brett