Overheating and the twin fans were not working?

2011 CHEVROLET IMPALA
220,000 MILES • 3.5L • AUTOMATIC
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SUNVALLEY0505
  • MEMBER
  • 1 POST
My Impala was overheating and the twin fans were not working with the A/C on high.
So I replaced all 3 relays under the hood, and also replaced the two 30amp fuses that are right next to the 3 fan relays. Still the twin fans did not work, so I disconnected the coolant sensor located under the MAP sensor.
Now, one fan on the drivers side works, but the other is dead.
So I am thinking on replacing the temp coolant sensor and replacing the twin fans. In the course of troubleshooting this problem, my A/C stop blowing cold air, it works, just blows hot air now.
Can you please give me some help on this problem.
Thank You,
Sep 16, 2026 at 8:26 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,464 POSTS
This might be two different problems, so if the AC is not working, (low on charge) the fans will not turn on. But if the engine is over heating they should go on. I would do is test the non-working passenger-side fan motor directly. Disconnect its electrical connector and supply battery power and ground directly to the motor. If the fan does not run, the motor-fan assembly is bad. If it runs normally, trace the fan circuit between the motor, relays, fuses and wiring connectors. Also inspect the fan connector closely for overheated or melted terminals. We should run the codes to see if any are stored. Here is a video to help

https://www.youtube.com/watch?v=LBCpCWEFnTg

Here is a video to help with the AC not working

https://www.youtube.com/watch?v=4UjfQKvrB6Y

We need more info to help fix the problem. Here is the radiator cooling fan wiring diagrams so you can see how the system works.
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Sep 17, 2026 at 11:18 AM
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