Friends,

I hear a humming noise of a low speed electrical motor turning followed by a series of clicking noises from underneath the dashboard cover, behind the radio. The noise sounds like a servo motor slowly turning; something like an internal HVAC vent flap that is trying to close a trap door/flap but is either stripped the actuator'* gears or something is preventing the flap from fully closing which would cause the motor to continually spin. The noise is heard only when the ignition is turned on, about the same time as the fuel pump kicks on, regardless if the HVAC is on or off and while driving the Lesabre. It sound like hum, hum, click, click, click, grinding electric motor gears noise. By the way, it seems I don't get full heat when the cabin heater is on, I am not sure if both are related. The noise does not go away even if I turn on the HVAC and select different vent settings. Any ideas?

Possible HVAC actuator......stripped gear and it is searching.......you will possibly have to drop the hush panels under the instrument panel, and remove the glove box......there is a ring on the outside of the actuator....if you see it moving, that is your problem.....

Dear Tech II,

You hit the nail on the head. I pulled the glove box and watched the HVAC actuator nothing was moving but making a noise. As soon as I unplugged the actuator, the noise stopped. I did remove the HVAC actuator and took the cover off; nothing appeared to be stripped out. I did manually twist the trap door open and closed several times, the flap did not want to stay closed by itself. I re installed the actuator and works fine, no more noise. I am not sure if the HVAC vent flap was stuck which was causing the discrepancy only time will tell. Thanks for the advice.

Friends,

The clicking noise is back. I did a little research and found a technical service bulletin, NHTSA: 10013102, TSB ID: 08262004. Anyone know how I can find out what the service bulletin is about and possible repair?

Visit a GM dealership; they should be able to look up the TSB for you. I have not had any real luck looking up TSBs on the net; seems they all want you to buy a service.