How To Test Acura RSX Cooling Fan

How To Test Acura RSX Cooling Fan


If you have a problem with your Acura RSX overheating, knowing how to test a RSX cooling fan can help. When your DOHC K series engine begins to run warm, it’s best to take immediate action so that you do not overheat your engine. Left uncorrected your overheating issue can cause your cylinder head to warp, which will lead to a loss of compression.

If you suspect your fans are not working or having a problem, this guide can help. Today I’ll be showing you how to test the RSX cooling fan in a 2003 Acura with the K20 engine in it. In order to test your RSX cooling fan you will need to use a digital multimeter or a voltmeter that’s capable of sending power to a wire.

Don’t have one? not to worry. You can use a 12 gauge wire with an inline fuse directly from your battery. If you are using this method to test your RSX cooling fan, make sure to take care and avoid shorting the wires together. To begin testing, make sure your Acura is turned off and open your hood to locate your cooling fan connectors. The fans are mounted to the backside of your Acura RSX radiator and can be accessed from the front of the vehicle.

testing a Acura RSX Cooling fan 1

When your RSX cooling fans don’t work, this easy testing guide can help you track down the issue. Here are some of the things that can cause an Acura RSX cooling fan to not work.

  • Bad Engine Coolant Temperature Sensor
  • Faulty Thermostat
  • Failed Acura RSX Cooling relay or fan switch
  • Faulty Acura RSX cooling fan

Remember that you will be testing the primary cooling fan and not the air conditioning or secondary RSX cooling fan. The primary one is the radiator fan located on the driver side of the vehicle.

Testing your RSX cooling fan

testing a Acura RSX Cooling fan 2The primary RSX cooling fan is connected with a two pin harness. When you need to test your RSX cooling fan you can begin by fashioning a ground wire.

Take a 12 gauge wire and crimp a female electrical spade onto one end. Connect this ground to your battery or chassis ground, and plug the female wiring spade into the B terminal of your RSX cooling fan.

Use the RSX cooling fan wiring diagram below to check which side PIN B is located on. Once you have that side connected, you must provide power. This is best done through a voltmeter that’s capable of sending 12 volts, but if you don’t have one you can use another wire like your ground unit.

testing a Acura RSX Cooling fan 5The power wire of your fan wiring harness is located at PIN A. Run the power wire from your positive battery terminal and connect it to PIN A.

The fans should kick on at this time. If they do this means there’s another issue with your cooling system in your K series Acura.

Your RSX controls the fans through your cooling fan relay. This part is also known as the fan switch. It’s located in the ECU panel under your hood. Before you remove and install a replacement relay, you should try to test your RSX ECT sensor.

Disconnect your ECT sensor and unscrew it from your RSX. Prepare a testing cup of boiling water and with the ECT sensor plugged in, dip the sensor side into the hot water. Your RSX ignition needs to be turned to the “ON” position for this part of the test to work.

If your fans kick over during this test, it’s a sign that your RSX fan switch or cooling fan relay has gone out. Replace it with a new one and you are ready to go. Have any questions about our guide on testing your RSX cooling fan? Leave us a message below and let us know!