89 Mercury Grand Marguis AUTO temp setting not working.
I have a vacuume issue that when I accelerate when the AC is in 'Auto' it stops blowing, deaccelerate and it blows cold again. Lately the 'auto' selection stopped working, but when in AC 'high fan' position it now blows HOT air on acceleration and cold when coasting, and the HEAT is winning in Florida. Mechanic replaced the EATC (Electronic Automatic Tempature Control) but this did not fix the Auto not working. I can live with this if I can get the Auto working again. Any ideas? My mechanic has none so far.

