1999 Mazda 626 Cooling and aircondition fans

1999 MAZDA 626
121,000 MILES • 4 CYL • 2WD • AUTOMATIC
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CALL2PREACH
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I recently took my car to a machanic to check the cooling fan and aircondition fan to see why they were not working and the car was overheating. He called me and informed me that he had check fan by by-passing the relays and the fan were operational. He concluded that it must be a computer problem or grounding problem but he could not locate the exact cause. I had the transmission rebuilt on the car about a mouth ago. He explain to me that it may be a gorund that runs to the transmission block. My questions is, what can be causing the the fans no to be properly grounded or could their be a computer problem, which I wasn't aware of any thpe computer boards in my car. Nelp fast!

Thank You
Apr 29, 2009 at 9:53 AM
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KHLOW2008
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Hi call2preach, Thank you for the donation. The cooling fan relays are controlled by the Power Control Module ( computer). Is the Check Engine Light showing? If you are able to retrieve the code, it would allow us to go into diagnostics to verify the source. Here are the cooling fan circuit.


https://www.2carpros.com/forum/automotive_pictures/192750_CoolingFan99Mazda626a1_1.jpg


https://www.2carpros.com/forum/automotive_pictures/192750_CoolingFan99Mazda626a2_1.jpg

Apr 30, 2009 at 11:13 AM
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CALL2PREACH
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No, the check engine light is not on. The only indicator warining I am getting is the thermostat guage is going to 'H' (HOT) when I am idle. What code are you refering to that I can retrieve that would allow you to go into diagnostics to verify the source.
Apr 30, 2009 at 1:09 PM
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KHLOW2008
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What I am refering to is Dignostic Trouble Codes.

Though the CEL might not be showing, there might be some codes stored in PCM. I would suggest getting a scan done to retrieve for codes.

Codes linked to this problem would most likely be P1460, P1464, P1474, P1479.

Does the A/C compressor work when engine is not overheating?
Apr 30, 2009 at 8:59 PM
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CALL2PREACH
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Yes the A/C compressor is working.
May 1, 2009 at 9:27 AM
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KHLOW2008
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When A/C is working, the fans do not come on at any time?
May 2, 2009 at 8:14 AM
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CALL2PREACH
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No not at all
May 4, 2009 at 2:57 PM
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KHLOW2008
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At PCM connector terminals # 17 ( Gray Wire) and # 45, use test lamp to ground them and check if fans comes on. If yes, the PCM is faulty. If fans does not come on, remove fan relays and with ignition switch ON, there should be 2 terminals with battery voltage.
May 5, 2009 at 11:12 AM