1991-1993 DeVille blower control module (power module) location
If you are standing in front of the car with the hood open, look left of center on the firewall for a cover that says "Maxi Fuse / Relay Center" remove this cover (two 1/4 turn fasteners on the front and one sheet metal wingnut on the top near the hood hinge). Underneath the fuse and relay center, you should be able to see the blower control module (power module) bolted to the top of the evaporator / blower module. Wires to the connector are color coded; Black, Purple, white and red.
Cadillac Man
Open hood . Disconnect blower module located near blower fan. Disconnect, if blower shuts off, repalce module
The blower control module is defective.
the resistor is located in the blower module which is located under the hood by the a/c evaprator case
on the blower module located on the A/C evaporator case R/S under the hood
behind the engine, next to the brake booster, a ring of 7mm screws finess it out wriggling it a little. replace the control module at the same time!!
power control module
The blower motors only work with the engine running. If the blower motor has three wires on the electrical plug, then the blower motor module is built into the unit & it's very expensive. Sometimes, you can tap on the motor with a hammer & it may work or slowly turn. If this is the case, replace the blower motor.
Behind the Left Rear Wing Panel
most likely a defective blower module under the hood
Under the hood, not far from the R/S hood hinge it's called a blower module
faulty blower module. Under hood not far from blower motor
P041 is "No Cam Reference Signal from the Ignition Control Module"