The cooling fans are set to come on when the coolant reaches 224 degrees (low speed) and 240 degrees (high speed). If they do not turn on (without the AC) then either your coolant does not reach 224, or the switch that turns them on and off is bad. The switch should not be hard to replace, or too expensive. Since you mention that they do come on with the AC, then we know it's not the fans themselves.
Cadillacs are notorious for blowing head gaskets. You may want to look into that.
a fuse or a bad fan motor
Could be a bad cooling fan on your Processer or a bad power supply.
If the problem your having is in your 'cooling system' , flushing it out could help out a lot.
Make sure that the fuse and sensor for the cooling fan are working. If these are ok then look at the fan motor, it could be bad.
You need to take your car into a service center as soon as possible. The fan is on constantly because there is a problem with your car. It could be your thermostat or cooling temperature sensor.
DRLs didn't become standard on Cadillacs until 1996.
Usually means you have had regular tap water in the cooling system resulting in corrosion. This could also result in the additives in the anti freeze not being affective or a sealant from a hole in the cooling system
An electrical problem.
There are several good locations to buy cadillacs in Calgary. For a new car, I would check out Jack Carter's located on 29th street. For a good used cadillac deal you could try CMP Auto on 36th St. NE.
Either the fan is no good or the heat sensor in your radiator, that turns the fan on is not working!!
not likely PCM problem... most common cause is either ... Bad Cooling Fan Relay Blown Cooling Fan Fuse or Bad Cooling Fan Motor