Hi,
I'm trying to track down an air con wiring diagram for a 1991 T4.
I have a pair of the Bently T4 manuals in excellent condition if you are interested.
Maybe you could photograph the AC wiring page? This is the only T4 thing I have, so not worth me buying the manual.
Maybe when i am home again and have the time to do so life is fairly full at the moment.
Thanks mate