1992 300sl

[Latham122]

Hi all. New to this. Picked up a 300sl with 40k. AC not working so just inquiring if anybody could point me in the right direction as to how to diagnose the problem myself. Thanks!

 

[mattkh]

If you can speak to the previous owner, then find out how long ago it was last used and
was it used regularly or not.

 

[LostKiwi]

Most common cause of AC failure is low gas. That would be the first thing I would have checked.
Second and third most common causes of failure are a bad compressor (lack of use dries out the seals allowing gas to escape) or knackered condenser (salt from roads corrodes them allowing gas to escape).
If it's not been used for a while you should replace the drier as well.

 

[Blobcat]

Most likely the gas has all leaked out, could be a failed condenser - quite common - rather than just throwing bits at it worth finding a decent local AC specialist - (not someone who's had 10 mins instruction on an automatic machine) and getting them to diagnose, leak test.