Everything worked fine yesterday....
Normally, when I turn the A/C on, the low speed fan behind the radiator
kicks on....today it did not.  The radiator fan does come on when the temp
gets up too warm, it also kicks into turbo stage 3 when it gets hot but
does not come on when the A/C compressor is on.  I checked the 30amp fuse
in the fuse box, checked the 50amp fuse terminals, eyeballed the stage 3
relay, can't find the stage 2 relay-supposed to be on the fuse block in 5
position-well there's never been a relay there before and everything worked
fine for 10 years until today.  I do have 12volts leading from the
compressor to the harness that runs to the front of vehicle (via the
red/blue wire connecting into the green/yellow wire).  As I recall from
some earlier checks, this wire would affect the fan when disconnected.
So, bottom line is - no radiator fan when A/C compressor is on.

Any thoughts???

Thanks for your wisdom.
Adolf