Cadillac Repair: 1991 Cadillac heater controls, heater core, fan motor

Question
What controls the flow of coolant through the heater core? Where can I find the control? We tested the fan motor and discovered it was bad...it's been replaced. We just can't get any heat from the heater core. Pictures available??

Answer
If you are mechanicaly inclined or know of someone who is, You will need a DIGITAL MULTIMETER, Simple 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.