Cadillac Repair: air conditioner controls, vacuum lines, c programmer

Question
why does my air condition switch from panel to windshield on the hottest of days. very uncomfortable.

Answer
You have a leak in one of the many vacuum lines on the engine or at the A/C programmer.

You will need, If necessary, Electrical schematics, Test procedures and picture locations of the components within the system that is causing you problems of which can't be done on this website which only allows one picture.  I do not have a website so you will have to e-mail: [email protected] in order to obtain the information.