Yes, when the a/c head pressure get too high.  Such as when idling in
traffic with little air flow removing the generated heat by compressing the
Freon.  Most likely will only happen with extremely high outside
temperature.  When it comes on it will sound like the space shuttle taking
off.

BobC

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Richard A Jones
Sent: Wednesday, June 27, 2012 3:04 PM
To: vanagon@GERRY.VANAGON.COM
Subject: AC and rad fan connection

'87 Syncro Westy.  My radiator fan has always come on "low"
when the AC was turned on.  Now, looking at Bentley 97.141, I see a
connection from the AC clutch relay to the third stage relay for the
radiator fan.  Is there a time when the AC kicks the fan on "high"?

Richard