Cadillac Repair: 87 blower motor, computer module, input comes from

Question
The power to the heater blower motor is hot at all times, ignition on or off, climate control in any setting, etc.  The wiring diagram shows the power input comes from the body computer module or the climate control power module.  Where do I find these parts and what is the most likely part to fail and cause the fan to be on all the time?  

Answer
The BLOWER FAN POWER MODULE is your problem which is located above the blower motor slightly to the left towards the passengers fender and is mounted on the top of the big black plastic housing that also houses the blower motor. It is held in place by 2 screws and has a multi-wire wiring hraness attached to it. When you remove it you will see a large finned aluminum component attached to the bottom of the module which is the heat sink.

Buy a new power module and then you can verify that you have the correct part.