Tapping under dash
Asked by MrBlank Aug 21, 2019 at 04:36 PM about the 2006 Chevrolet Trailblazer LT RWD
Question type: Maintenance & Repair
I have a tapping sound coming from my dashboard it is not
all the time but it is getting to be more and more and it is a
steady tick not loud doesn't seem to be doing anything but
concern and wonder what the noise could be coming from
my 2006 Chevy trailblazer dashboard
2 Answers
Usually that sound is your HVAC vent actuators. Look up how to reset them, I don't recall the procedure. If that doesn't work, they need to be replaced. It's either your blend actuators (hot/cold) or the actuators that switch from floor, head, or defrost. This will happen a lot of times AFTER the batter was disconnected and reconnected for any reason. Bad design.
Yes, running the recalibration may help, but if it is clicking, that usually means the internal gear has broken. Procedure; 1) key off, pull fuse #36 & 39 in the rear fuse box. 2) wait about 90 seconds, then put fuses back in. 3) turn key to ON position (not Start), don't touch any HVAC controls for at least 90 seconds while calibration runs. Turn key off. 4) start truck and check for noise and operation of HVAC system. It is called Recirculator Actuator; AC Delco# 15-73597, GM# 89018677