A friend is checking out a 91 vanagon and has asked me to post these 
questions:
 The van is equipped with an automatic transmission that currently 
appears to be filled with gear oil rather than Dexron. Can this  have 
caused or perhaps be masking any problems?
 Secondly, the AC compressor doesn't turn on - there is some freon in  
the system - is there a pressure switch, and/or is  it so that this AC 
set-up is also tied into the ECU? How would one diagnose where the 
problem lies?
 Thanks.