Another AC question, this time related to my 1991 405 DL: when turning the AC on, there's a hissing noise coming from the dash. This has been going on for a while, with the hissing getting progressively worse. The pitch of the noise is RPM-dependent and the air is not as cold as it used to be. Any ideas on what might be wrong (a leak somewhere)?
Thanks,
Radu
Austin, Texas
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