A/C Blower Control Module

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Feb 16, 2013 | 06:41 PM

watson

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Drifting

Joined: Aug 2004

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From: Carmel CA

A/C Blower Control Module

My 93 has the electronic climate control and my heater/AC fan is not working. I checked the one wire connector at the blower control module and it shows 12 volts with the fan set a speed 8. I do not get a reading on any of the three pins on the module that connect to the other connector. Am I correct in thinking that the module is bad? Is there a test that I can do to check it out? I first planned to just replace the thing. Then I saw the price for a new one and I decided to try and be sure that I need one.

Thanks,

Doc

Feb 16, 2013 | 06:54 PM

vetteoz

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Should be 12V on the 2 wire connector full time because that is the feed from the battery.
Pull the A/c fault codes
https://www.corvetteforum.com/techti...=193&TopicID=2

and see if any controller faults showing

FSM says check the CTSY , A/c and underhood A/c fuses ( from '90 FSM )

Last edited by vetteoz; Feb 16, 2013 at 06:57 PM.

Feb 16, 2013 | 06:59 PM

watson

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Drifting

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From: Carmel CA

Thanks, I will give that a try.

Doc

Feb 16, 2013 | 07:23 PM

watson

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Drifting

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From: Carmel CA

I believe that I ran the codes correctly and it showed code 127. Code 128 should indicate 14 volts, so does this indicate that my control module is getting power and the fan motor is the problem. Or does it say that the module is the problem?

Thanks

Last edited by watson; Feb 16, 2013 at 07:27 PM. Reason: typo

Feb 16, 2013 | 08:11 PM

vetteoz

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Quote:

Originally Posted by watson

so does this indicate that my control module is getting power and the fan motor is the problem.

Unplug the blower motor connector and run 12V ( and a ground ) there and see if the motor actually runs correctly as a starting point.

Feb 16, 2013 | 09:14 PM

Hooked on Vettes

Melting Slicks

Joined: Aug 1999

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From: Baltimore, MD USA

The Red wire is 12 volts for the Blower Control Module and is also
the voltage used to power the blower motor.

Black wire is ground.
Purple wire is the output voltage from the Blower Control Module
to the blower motor.
Tan wire is the control voltage from the AC Programmer to the Blower Control Module.

If you manually set the blower speed 1-10
the voltage on the Tan wire should be vary from 2-7 volts.

Remove the 4 pin plug from the Blower Control Module.
Turn the ignition On and set the blower speed to 10.
You should measure around 7 volts DC on the Tan wire.
If you read zero, something is wrong with the AC Programmer.
That's a black plastic box mounted on the firewall above and
to the right of the gas pedal and has vacuum hoses going to it.