Cadillac Repair: a/c heater and power steering, odd miles, eldo

Question
Hello, I have 2 questions about my 1990 eldo.Where is the a/c heater programer located exactly around the passenger side. Under the hood or inside the car. I must change this part. Also I changed my power steering pump, and reservoir. There are no leaks, but still there is a rather loud wynning I hear. So I changed the pump again thinking it was faulty. I tried to work the air out by driving, but I've driven over a hundred some odd miles already. Please help me with my 1990 eldo.

Answer
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: onlineautohelp@msn.com in order to obtain the information.