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heater clicking noise

Discussion in 'Chevy Trucks' started by rbi014, Oct 16, 2010.

  1. rbi014

    rbi014 Junior Member
    from 44131
    Messages: 19

    2004 2500HD. When the dual heat control levers are pushed all the way down for cold air, there is a clicking noise coming from under the dash. When levers are pushed up noise goes away.

    I've tried to locate the noise but can't seem to isolate where it is coming from. I suspect the noise is coming from an actuator - any ideas on where the actuator might be?
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    You're on the right track to suspect an actuator and it would be either of the two air temp door actuators. One controls the driver side temp and the second of course controls the passenger side and it may be either one you're hearing. Easy way to narrow it down those since you discovered moving the temp sliders changes the sound, simply move only one of the sliders at a time instead. This will clearly show which actuators is causing the noise. The passenger side actuator is located on top the HVAC box, approx behind the ash tray. It's a little tough but it's accessible through the glove compartment. The driver side one is on the bottom of the box, right above the trans tunnel. Access to it can be had by removing the trim cover below and surrounding the HVAC box. Small hands with good dexterity really helps for these tasks.

    Once you've performed the work the HVAC system needs a quick re-calibration. To do so simply remove the HVAC fuse for about 1 minute, replace the removed fuse and start the truck being sure ALL HVAC controls are set to the off position. Allow the truck to idle for approx 1 minute while the HVAC module re-calibrates the actuators and you're all set.

    There's also a TBS for a reflash on the HVAC module to address clicking noises that stem from the actuators that some trucks need but yours will still need the single noisy actuator replaced first. Once you have that done then check with the local dealer about the re-flash, using the VIN they'll be able to identify if yours requires it or it's already been done. Just mention TSB bulletin # 06-01-38-003 and it should ring a bell for them as it was a very common issue on '03-'06 GM trucks.
  3. Q101ATFD

    Q101ATFD Senior Member
    Messages: 277

    Actually, I would go get the reflash update before I replace the actuator. The clicking you hear is the plastic gears stripping. If you put a new actuator in before the reflash, you're damaging the new unit. You can also tell which actuator is broken by changing the temp sliders from hot to cold/cold to hot, and whichever side does not change with the sliders is the one that's bad. As said above, the drivers side one is easy - I did mine last week in 10 minutes. Shop around online for the part, I got mine for $90 shipped.
  4. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    The brief time period between changing the actuator and getting a re-flash done if needed won't hurt it.