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.
Where is the relay for cooling fan?
The fan relay is usually located
near the bottom of the engine compartment on a metal frame member
. The metal acts as a heat sink to keep the fan relay cool. So, unplug the connector at the relay and repeat the check for power. If you get power, you've got a bum relay.
How do you replace a 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.
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.
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.
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
.
How much does a fan relay cost?
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.
How do you check a relay?
- Locate the relay you need to test. …
- The quickest and easiest way to test a relay is to swap it out with a known good replacement. …
- Grab a multimeter and set it to Ohms. …
- Leave the multimeter on ohms or continuity. …
- Energize the electromagnet coil with a 9-12V battery across the pins.
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.
Why does my radiator fan not turn on?
If the fan doesn't come on,
you need to look for a blown fuse or breaker
. In older cars, you might have a fusible link – this is wire within an insulated block of rubber. Try to grab the end and stretch it. If the wire stretches, the wire link could be broken and you'll need to replace it.
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 test a Thermo fan switch?
Turn on the burner and slowly
increase the water temperature
. The ohmeter should be turned on and have a reading of high resistance. When the water reaches between 180 to 220 degrees Fahrenheit, the switch should turn on and the resistance seen by the ohmmeter should change to zero.
What causes a fan to stop working?
Poor ventilation can cause dust and heat to get trapped inside the case of the motor
. This can cause your fan to stop functioning—especially if your fan has an overheating feature that causes it to automatically shut off if it gets too hot.
When should your cooling fan turn on?
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
.
