The cooling fan relay is normally located in either
the underhood fuse and relay center
or mounted to the electric fan assembly behind the radiator.
How do I know if my cooling fan relay is bad?
- The engine runs hot or overheats. …
- The cooling fans don't work. …
- The cooling fans keep running. …
- Warning lights. …
- Poor air conditioning performance. …
- Swapping Relays. …
- Measuring the Relay Coil's Resistance. …
- Listening for Noises.
How do you replace a cooling fan relay?
- Materials Needed.
- Step 1: Locate underhood fuse/relay box. …
- Step 2: Remove the fuse/relay box cover. …
- Step 3: Identify the cooling fan relay. …
- Step 4: Be sure power is off. …
- Step 5: Replacing cooling fan relay.
Where are cooling fans located?
The electric cooling fan is typically mounted
behind the radiator
. On some vehicles with large, wide radiators, there may be two cooling fans, or there may be a separate fan for the air conditioning condenser. The fan only runs when needed to help cool the engine.
What tells the cooling fan to come on?
The engine temperature should trigger the fan to turn on
. It will also turn the fan off once the engine has cooled to under 200 degrees. You may have heard of a part called the radiator fan switch or temperature fan switch. This is linked to a thermostat and works much like your home's HVAC system.
How do you check a fan relay?
- Look at the markings on top or side of the relay case and locate the two control circuit terminals, which connect to the relay's coil, and the two power circuit terminals, which let electrical current pass to the fan. …
- Connect the leads of an ohmmeter to the power terminals on the relay.
What does a bad fan relay look like?
Engine running hot
One of the first symptoms commonly associated with a bad or failing cooling fan relay is an engine that runs hot or overheats. … If the relay shorts or fails, it will not be able to supply the power for the fans to operate and keep the engine running at normal temperatures.
How much does it cost to fix a cooling fan relay?
To get your cooling fan relay replaced, you will pay, on average,
$80-$160
, depending on the type of car you have and the mechanic's fees. The labor should cost around $70, while parts should run you $10-$50.
Should radiator fan turn on when AC is on?
Both radiator fans should always run when the AC compressor is engaged. To check the temperature at which the fan comes on, turn the A/C off and keep the engine running until it reaches normal operating temperature. Most fans should come on when the coolant reaches
about 200 to 230 degrees
.
Does the coolant temp sensor control the fan?
The sensor works by
measuring the temperature
that's being given off by the thermostat and/or the coolant itself. The temperature is then sent to the on-board control system. … As the control system receives the temperature from the CTS, it may trigger the cooling fan to either shut off or turn on.
Can a bad thermostat cause radiator fan not to work?
Broken Thermostat
Thermostats are known to go bad and cause all sorts of cooling issues. … If this thermostat doesn't open when the engine reaches the working temperature, the coolant will stay inside the engine block and the engine
will start to overheat
. This will result in the radiator fan not working.
Why does my radiator fan not turn off?
Pull the cooling fan relay out of the box
. Replace the cooling fan relay with a new one. A stuck closed relay is the only thing that can operate the cooling fan continuously with the key off. The computer looses power with the key off and the same applies to the coolant temperature sensor.
What sensor controls the radiator fan?
On most modern cars, the cooling fan is controlled by
the Engine Control Unit (ECU)
which gets a signal from the coolant temperature sensor.
How do I know if my coolant temp sensor is bad?
- Poor Fuel Economy. …
- Irregular Temperature Readings. …
- Black Smoke from Your Exhaust. …
- Your Engine is Overheating. …
- Your Check Engine Light is On.
What are the signs of a bad temperature sensor?
- Poor fuel economy. One of the first symptoms associated with a problem with the coolant temperature sensor is poor fuel economy. …
- Black smoke from engine. …
- Overheating engine. …
- Check Engine Light comes on.
