Cooling Fans will not turn on

2008 CHEVROLET MALIBU
195,300 MILES • 2.4L • 4 CYL • FWD • AUTOMATIC
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SHALEN WILLIAMS
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  • 2 POSTS
The cooling fans will not turn on causing the engine to overheat.

I have already replaced the engine coolant temperature sensor and both fan relays. I have tested the wires from the sensor to the ECM and ground and they are good. The fans come on 100% when I unplug the coolant temperature sensor for safe mode. I also replaced the relay for the air conditioner compressor and that system works correctly (I read that the two systems are connected).

I am at a loss, any help would be wonderful.
Jul 27, 2016 at 8:48 AM
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HMAC300
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  • 48,601 POSTS
I am assuming you have checked the fuse as well for the fans along with the relays which you said you did. there are three relays for fans and ground is near #4 exhaust port. also check ground for fans and diode might be messed up. see pictures.
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Oct 28, 2020 at 6:09 PM
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SHALEN WILLIAMS
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Yes, I checked the fuses as well. I will check the grounds when I get off work this afternoon. If the ground was not connected wouldn't that keep the fans from coming on at all?
Oct 28, 2020 at 6:09 PM
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HMAC300
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if the ground is poor or disconnected the fans wont work. the fan grounds may be on the header where radiator is bolted to.
Oct 28, 2020 at 6:09 PM