probably low on refrigerant.
my 88 with R-12 would blow 34 out of the vents with an outside temp of 90 .
my 99 crown vic and 02 diesel pickup will get down to 38 unless it is over 90 outside, then it will be between 40-42.
Alleged Moderator of the "not wrapped too tight forum"
owner of almost too many fords.