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RussMasterTech, ASE Certified Technician
Category: Chevy
Satisfied Customers: 791
Experience:  19 years of GM Dealership experience. ASE Master with L1 and GM Master Certified in Electrical
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On my 2006 Cobalt, the rear window defroster does not work,

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On my 2006 Cobalt, the rear window defroster does not work, the vent settings cannot be changes (I.e. Defroster, floor, normal vent), the A/C will not turn on, I can't change whether or not the HVAC recirculates, and I can't cycle through the odometer, trip, etc. in the information center.

All fuses have been checked and are verified to be good with a multimeter under the hood and in the passenger cab in the kickpanel on the passenger side.

Does this sound like it could be a BCM that is so common with these cars? or is there something else to be looked at.

The vehicle has exceeded the 36,000 mile warranty by three thouseand miles.



I looked at the schematics for the HVAC on your Cobalt. There is a fuse located in the BCM/fuse block, fuse 16 that is for the HVAC and IP ign feed. If you are not getting power to this fuse, it could be a BCM like you say. Use a 12 V test lamp and check for power on both sides of that fuse and if it's blown replace it. If you have no power at all to that fuse with the ignition on, let me know.


I'll send the schematic along for you to look at as well.


Hope this helps.


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RussMasterTech and 2 other Chevy Specialists are ready to help you
Customer: replied 8 years ago.
That fuse was blown when I began testing initially a few hours ago. I replaced it and thought it was fine. I just checked it again, and it is once again blown. What would cause this fuse to blow like that?

You most likely have a shorted wire between the BCM and the HVAC head or between the BCM and the Cluster. You should disconnect the HVAC head and see if the fuse blows again. If not, it could be something down the line from the HVAC head. It could be a wire going to one of the actuator motors that move the temp and mode doors. It will take some detective work to find which wire or which component is shorting out.


If you put another new fuse in, try to see if it blows right away when you turn the ignition on or if it only blows when you move the HVAC knobs to a certain position.


Good luck. Let me know what you find. Also, let me know if you need any more schematics or procedures for removing components. I'd be glad to help.



Customer: replied 8 years ago.

The fuse blows right away when the ignition is turned on.


The radio bezel looks like it may be a whore to remove, is there a plug to the HVAC control head accessible without remover the center console?


It looks like the face plate is just held in by clips.

Instrument Panel Center Trim Panel Replacement
Object Number:(NNN) NNN-NNNN Size: LF


Component Name


Preliminary Procedure

  1. Remove the right I/P trim panel.
  2. Remove the driver information center (DIC) switch.


Instrument Panel Trim Plate Assembly


  1. Pull out on the trim panel in order to release the retaining fasteners.
  2. Disconnect the electrical connectors.


Instrument Panel Trim Plate Clip