1998 CHEVROLET M SERIES Electrical System Problems

WE'D ONLY OWNED THE CAR ABOUT 2 YEARS (WE BOUGHT IT ONE YEAR USED) WHEN THE A/C STARTED HAVING PROBLEMS. AT FIRST IT ONLY WORKED ON LEVEL THREE OR HIGHER, THEN IT QUIT BLOWING COLD AIR. TO GET TO BLOW COLD AIR CURRENTLY, WE HAVE TO CONSTANTLY PROMPT IT BY PUSHING A BUTTON. WE HAD THE FREON REPLACED TO NO AVAIL. OUR MECHANIC SAID IT SEEMED TO BE A DEFAULT WITH OTHER CHEVYS, ESPECIALLY MALIBUS AND ESPECIALLY ONES MADE AROUND THAT YEAR. I KNOW TWO OTHER PEOPLE WHO OWN MALIBUS AND THEY HAVE THE SAME PROBLEM. WE'D LIKE TO FIND OUT HOW TO GET IT FIXED AT GM'S COST. IN ADDITION, MY HUSBAND WORKS FOR A GM FINANCING COMPANY.