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Hello! I NEED some help!

I have a 2002 Honda Civic Ex and I just found out that when I turn the A/C on, air blows through the vents, but the fans don't spin until the car tries to cool the engine down. What could be the issue here?

 
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I would wonder if the AC system is actually working and cooling, and if someone has done some creative wiring to bypass some problem area.


I would connect my scanner to see (datalist) if the PCM is getting the request from the HVAC system, and view the status of the command for the fans to run at that time. Then test to see if the PCM really is doing the right thing to run the fans.

The radiator fans are controlled by the same relays no matter if the coolant temp switch turns them on, or if the AC tells the PCM to turn them on.
The coolant temp switch can run the fans by itself, but the AC system makes the fans operate through the PCM.
You know the fans do turn on when the temp switch tells them to......that leaves the circuit to run the fan relays from the PCM in question.

Sooooooo in lieu of a capable scanner, I would get a voltmeter and backprobe PCM terminal B6 and measure voltage.

Key on /engine off /fans off you should see battery voltage at B6.

If you unplug the temp switch on the engine and jumper the harness connector with a paper clip the voltmeter on B6 should read 0 volts because that jumper just grounded the circuit.

Undo the jumper, voltmeter should return to battery voltage.

Turn on the AC (switch and fan), the voltage should go to 0v again as the PCM tries to trigger the relays to operate the radiator fans.



With a good wiring diagram for the system I would see if I get continuity on the wire in question from PCM B6 to junction connector C102. These are all behind the glovebox, and the lead from the temp switch ties in as a junction in C102.

 
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Update: 2019

I changed a few things with the 2002 Honda Civic Ex and I remember hearing a whistling or like a high pitched whine type sound shortly after
the cooling fans turn on to cool the engine down. I have been getting by not having the car overheat by revving the engine when it starts to overheat,
but I feel this sound has something to do with why my cooling system is not functioning properly.
So far it has been about 1 year since I changed the cooling fans, head gasket, thermostat, radiator, water pump and belts. When I got the head gasket changed,
I had to rev the engine to cool it back down when it is idling. Other than that, the car doesn't overheat at all.

Here is the link to the video where the car makes the sound:


Please help me diagnose this sound! I love this car and I feel as though this will help me fix the issue once and for all.