HVAC controll unit

My 1991 348 TS a/c control unit is acting crazy! sometimes it works and sometimes it does'nt hit a bump and it works on full fan speed and then i can tap on the side of the console and it stops working all together. where can i send it to geti repaired or purchase a good used one? I called ferrari of north america and they sadi "we used to send them out and get them repaired but not any more" PAAHHHLEASE HELP!!!!!

 

First thanks to all who reply this post!!!!!! I did the 30K motor out service in april and the a/c control didnt then and didnt work when i bought the car but it was nice weather out so wasnt worried about it then but when i put the motor back in and got everything plugged up with a new battery the a/c unit worked for about three days and then here we are again and its hot and humid and no a/c makes my girl a mad lady!!!! so i took the unit apart cleaned inspected solder joints and fixed the fuse up front checked power and ground which are good checked all the wires
going to the unit and are good so i need a unit or send mine off!