Just a reminder, there are two controls for the A/C on a Westie.  The inner
knob is for fan speed the outter ring around this knob is for temperature
control.  You need to not only turn the fan speed knob, but the temperature
knob should be maxed out as well in order for the compressor to come on (in
other words you need both knobs turned and people do overlook this fact).  If
you turn both controls on and nothing happens then you have an electrical
problem because the earlier A/C systems (up to '86) did not have any pressure
switches in the system so the compressor is always on as soon as the knobs
are in the proper position.  Another common problem is that the knobs or
switches that control the A/C are broken.  They are NLA from the dealer so
good, used is your only hope (unless you want to make your own switches).  
Hope this helps.

Thanks,
Ken Wilford
John 3:16
www.vanagain.com
Phone: (856)-765-1583
Fax: (856)-327-2242