I know this is not T-bird or Ford related but just information I recently discovered. The A/C on my 2000 Malibu would ice up after about 70 miles. I have worked on all types of refrigeration and A/C's for about 40 years and tried to find a cycling switch but there was none on this car. After a lot of research I found that this has a Variable Displacement Compressor that runs all the time. It has a valve inside that uses pressure to vary the stroke of the pistons. My valve was bad so I replaced the compressor. New challenges keep life interesting.