In my 06 Equinox, my A/C will freeze up so to speak. I will have it running and its blowing ice cold air, then the air slows down almost to a stop. I turn off the AC switch and then in a few minutes the fans is back blowing full force. I switch the AC back on...then repeat after about of 20 min of driving. I have tried just temp control, but will freeze up either way. Have had a the shop and there is no leaks and system is fully charged. I changed the in cabin filter and that also did not work. Is there something I could look for such as a sensor switch or another filter somewhere??