Are there2 heter fans in 02 deville - 2002 Cadillac Deville

3 possibles 1 fuse 2 blower motor resister 3 blower motor itself

So you're getting heat, but the blower fan itself is not working (hot air comes from open vents, but not "forcefully blown in" from the fan? Were you hearing any squealing noises when the fan was on, before it quit working? If so, your fan motor is probably dead. It could also be the fan switch, or a fuse or relay. in the circuit.

If the fan speed settings are not working then it will most likely be resistor fan switch or it could be that the resistor plug isn't pressed in all the way

Check the air flow for any blockage or desviation because on hwy speeds.the car donot need use the fans like in the strets.

Assuming the cooling system is full, I would have the computer checked for trouble codes first.
The codes will point you in the right direction to diagnose the problem, but not tell you what to replace.
Depending on how it overheats, problems could include a bad thermostat, faulty cooling fan, or other issues.

Below is the master help link provided to go through belt routing diagram:---Timing belt, drive belt, serpentine belt, accessory belt, fan belt, engine belt routing diagrams for all types of car models?
Click the link below: ----

http://carbeltrouting.blogspot.in/2012/02/timing-beltdrive-beltserpentine.html
----------This will help. Thanks.

The fan resistor block is usually located under the passenger side dash, on the side of the heating/cooling assembly. It is located there so the air blowing threw the duct will cool the resistor block to keep the wires from melting. If you don't readily see it by looking under the dash, you may have to remove the glove box to find it - hope this helps - good luck :O)

search ( mitchell1diy) this is a repair site you can access.

there is an electrick switch moter located on the heter box it is very hard to fix rely on certified help

look under the glove box. You should see the blower motor and a resister right beside it. I think it has 4 wires going to it.