This is something I've wondered about as well.  I, too, have an '85 that 
     I've noticed the needle rise close to the limit without the fan going on.
     
     I've checked the 2-position switch on the radiator and it turns the fan on 
     when shorted.  I've also looked in the Bentley at the wiring diagram, which 
     shows that the temp indicator is wired to the switch at the engine while 
     the fan is controlled at the radiator.  In addition, the cooling system 
     bleeding procedure suggests that the engine needs to be turning above 
     2000rpm for adequate circulation of the coolant.
     
     All of this, in my mind, indicates that when the temp needle starts to rise 
     at idle, we need to rev the engine and let it "idle" at +2000rpm.
     
     Any comments?
     
     Pat S.

______________________________ Reply Separator _________________________________
Subject: Re: engine cooling non-problem
Author:  ajax@why.net (ajax) at INTERNET
Date:    3/21/96 1:04 PM

I have an 85 GL and it too rarely turns the cooling fan on.  However, 
the gauge does rise pretty far when at a prolonged idle.
 What I've wondered is whether the 
gauge measures the temp at the engine or the radiator.  I know the 
fan is switched at the radiator.

If it is at the engine, then it could be that the water pump is not 
circulating the coolant to the radiator sufficiently to cool the 
engine and thus the radiator never turns on but the engine is indeed 
running hot.  Let's face it, it is a long push from the engine to the 
front of the van.
                       
 If it is at the radiator, then I don't think there is a problem.

Does anybody know?

Greg
Gregory V. Robinson
ajax@why.net
tcdfw@aol.com (TwinCell: 2 Cellular Phones / 1 Number)
85 BMW 535i 157K  (BMW Digest)
85 VW Vanagon  135K   (Vanagon List)