Fans not working, how do I test the fans?

Tiny
TODD ANDREWS
  • MEMBER
  • 2009 CHEVROLET IMPALA
  • 3.9L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 104,000 MILES
My fans are not working changed relays fuses are good. Changed temperature sensor and thermostat. How do I find out if my fans are good?
Saturday, August 13th, 2022 AT 7:33 PM

1 Reply

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,747 POSTS
Hi,

I realized the fuses and relays were checked. However, did you confirm there is power to them when needed? Did you check all three fuses and relays?

If you haven't, follow the directions in this link for testing a fuse (for power) and the second link is for checking a relay.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

If you have already checked and confirmed they are good, the next thing I want you to check is there is a ground for the blower motors.

Disconnect the right-side fan. There should be a light blue wire and a black one. Check the black wire for continuity to ground. Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-wiring

If that checks good, then to check the fan motors themselves, you will need to disconnect the connectors at the fan motors. Then run jumper wires from the battery positive to the white wire on the left fan first. Then provide a ground wire to the gray wire on the same fan. Once both are applied, the motor should run.

You will do the same for the fan on the right. However, power will go to the light blue wire and ground to the black.

When you do this, make sure not to short the jumper wires together.

Let me know if this helps or if you have other questions. Additionally, I attached the wiring schematic below to help guide you and provide a reference.

Take care,

Joe

See pics below. Note: I cut the page in half to make it readable. I did overlap the two so you can follow from one to the next.
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Sunday, August 14th, 2022 AT 8:36 PM

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