Where are the cooling fan relays located on the 2000 Cadillac Deville ?

They are between the fans behind radiator.

Engine Cooling Fan Relay 1
In the center front of the engine compartment, on the lower radiator support, near the cooling fans
Engine Cooling Fan Relay 2
In the center front of the engine compartment, on the lower radiator support, near the cooling fans
Engine Cooling Fan Relay 3
In the center front of the engine compartment, on the lower radiator support, near the cooling fans

Two cooling fans controlled by three relay's . If only one fan is working ,that could be a problem .
Coolant Level Sensor Description
The coolant level sensor monitors the coolant level in the cooling system and indicates if the coolant is low. This sensor is located at the base of the radiator surge tank and is not serviceable.
CHECK COOLANT LEVEL (2)
The IPC receives a discrete input from the engine coolant level switch. The engine coolant level switch is normally closed. When the engine coolant is low, the engine coolant level switch opens. When the IPC receives an open signal from the engine coolant level switch, the IPC displays the message on the DIC.

Relay Driven Dual Cooling Fan Diagnostics There are using a pontiac , by your cadillac is the same .

Both the start circuit breaker (30A) and Start 1 relay are located in the underhood fuse block.

most likely a bad fan motor or an open circuit.

There are three cooling fan relays in the fuse block under the hood.




The fan relays above are numbered 37,39 and 40

Relay 37 is RH fan
Relays 39 and 40 are LH fan.


You can check if your fans are working by switching on the air con.
Are you having overheating problems?

Regards.

Are you sure that you don't mean the cooling fan control module? It should be located up front next to the cooling fan. It is square shaped and has a long square shaped plug going into it. Reads the temperature of the coolant and passes the information to the engine control computer (ECC). The ECC receives analog information and signals the cooling fan switch to cycle the cooling fan on or off, as required.

a relay panel is located under hood on passengers side

check fans,relay under hood on passengers side,and replace cooling fan sensor

Left Hand Side Of Engine Compartment On Relay Bracket