2003 Chevrolet Malibu coolinf fan

2003 CHEVROLET MALIBU
85,000 MILES • 3.1L • 6 CYL • 2WD • AUTOMATIC
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RAYJROB
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  • 8 POSTS
my cooling fans don't come on even when my temp gage goes to red .I took the cover off the relay and engage it manually and they come on . the relay isn't getting the 12volts to the coil to engage it.
Sep 9, 2014 at 5:41 PM
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JACOBANDNICKOLAS
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  • 110,175 POSTS
The coolant temp sensor sends the signal to the PCM to engage the fans. Check the sensor first, check wiring between the sensor and the PCM, and check PCM if needed.
Sep 9, 2014 at 5:54 PM
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RAYJROB
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  • 8 POSTS
how do I check the pcm
Sep 9, 2014 at 6:11 PM
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RAYJROB
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if the gage works does that mean the sensor is working properly
Sep 9, 2014 at 6:12 PM
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JACOBANDNICKOLAS
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  • 110,175 POSTS
I can't remember for sure on an 03 and can't get to my manuals, but some of these vehicles have a temp sending unit for the gauge and a coolant temp sensor for the fans and so the computer can determine proper fuel mixture based on temp.

From what I remember, the relays get power from the underhood junction box. Have you checked for any blown fuses there? Also, I believe there are three relays and they run in a series for your system. Have you found 3 and been able to check if all don't have power?
Sep 9, 2014 at 6:24 PM
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RAYJROB
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there are no blown fuses and 2 fan relays I have power to the line side of the relay but not the coil
Sep 9, 2014 at 6:49 PM