re: A/C questions 4K

[Sdthrl <Sdthrl@aol.com>]

You inquired about the A/C compressor/rad fan operation on your 4K and have
had a little BTDT with my '86 4KCSQ.  As the other "lister" in California
answered, the pressure switch is what operates the rad fan on my car as well.
Here in the mid-west, A/C is pretty popular stuff and when I purchased my 4K,
it was weak at best.  Now is OK, at best.  Never had it too cold in this car.

Your sight glass is under the top plastic cover for radiator ducting (two
screws).  Also you will see the receiver/dryer (which I replaced) and the
pressure switch located on the top of the receiver/dryer (which I should have
replaced, it leaked).

Just for info, you might check the evaporator located behind the glove
compartment.  When I removed the drip tray, I found the bottom surface of the
fins about 80% clogged with lint, dust, whatever, effectively blocking air
passage through the evaporator.  Cleaning this helped efficiency of the unit
quite a bit. 
Operation of the A/C involves recirculated air from inside the passenger
compartment and proper sealing and operation of the fresh air/recirc door
located in the cowl area important. 

One other thing, my heater control valve was leaking hot water constantly
through the heater core in full cold position which drastically affected the
temp of the A/C air.  The valve was $18 from the dealer. 

Hope this helps.

Phil (Sdthrl)
4KCSQ  52K (each your heart out)
5KSQ  96K (only glass sunroof in the world)