I also have that happening as of this morning.  I picked it up from the a/c
shop and started and really loud tick-tick-tick. I have heard this will go
away, but I drove about a mile and still there.  Left it at the a/c shop cuz
I have another issue I will post seperately, but wanted to make sure nothing
to worry about, also.
Michael in San Antonio
91GL Weekender AT 2.1L 'Gringo'