Cadillac 1999 DeVille
If the front
blower motor is not running with battery level power to it, you may have bad blower resistors which controls the speed of the motor.. Unfortunately the resistors are built-in the motor. You may have to replace the motor. If you remove the motor, you can recheck it by direct wiring power to it. OR you may have loose wires.
Also check the Heater and A/C Programmer module.
Here's some info I found from another posting.
Red is positive 12 volts coming from fuse of circuit breaker. The black wire is either the ground or the main hot wire going to the blower
motor (3 pin connection only), and the gray wire (if is is small in size) is a variable voltage coming from the body control module requesting speed for the blower
control module varies voltage on the main wire going to the blower
motor, supposedly in accordance with the requested voltage from the body control module. Usually if all fuses are okay and present on the apprpriate wire of the blower
control module, the a blower
motor that will not run or stays running after the key is turned off is the fault of the blower
control module. If the blower
control module has failed the the cause must be determined (over amping blower
motor) or else new blower
control module may fail when powered up.Usually blower
have more than three wires. Usual connections are: B+ (battery voltage) GND (chassis or engine ground), two large wires going directly to blower
motor (can be any color, but are usually 10 guage in size), and an optional wire that reports voltage level back to the body control module.