The '80-'89 Bentley manual list an ambient air temp sw on current 
track 15 but the schematic doesn't show a separate one like on '86 
on.  THere is however what appears to be a switch in-line with the 
compressor relay,integral to the dash mounted switch, that is in 
addition to the ac thermostat switch, which also controls the 
compressor(Love that Sentence Structure).  I would bet that on the 84-
85 the ambient air temp sensor is integral to the dash-mounted fan-
speed/air cond temp switch.

Currently, we are having unseasonable warm temps in Northern Minn.  
It's actually 32.3 F as I write this(I take temps for the Nat Weather 
Serv.).  Soon it will drop to -35 F and I'll be able to test all our 
theories on ambient air switches.  This is how I've gotten my ac 
compressor to run in winter (real winters, mind y'all).  Since I 
don't have a heated gargage, I take the van into our local heated car 
wash, wash all the salt off (why plow roads when you can just salt 
the $%#& out of 'em?), and when I drive out the van is warm enough to 
activate the ac for a brief but satisfying period.

Now to cast doubt on my above theory, if I am correct in the 
location being integral to the dash switch, I should be able to 
activate the compressor anytime the interior is warm enough 
(actually, a not altogether frequent occurence).  I don't remember 
that being the case!  The things we are oblivious to, eh?  Cold 
weather testing to take place shortly!

Daniel Houg
Minnesota Department of Health
Internet Address:  fairwind@northernnet.com
Fax #:  218/755-3823