99Yak
I'm Awesome
I have a 1999 k1500 Suburban. When the AC (front) is on there is noise that seems emanate from the deep center of dash. Best description would be a low grind, but maybe whirl or even a buzz. It goes away if you turn the knob to left - off position. Or press the the lighted AC toggle. Or when the vehicle stops.
I assumed it was an issue with the center blend/mode actuator or door, because it sounds like, maybe, nylon gears stripping. But, the noise accelerates with the engine. So how would acceleration relate to the actuator?
Any thoughts?
One more piece of information: The mode (?) doesn’t always change immediately. ( Mode is floor to dash to vent. Correct?).
Edit———————
- Changing the Mode is slow or delayed sometimes. Especially Dash Vents Only. However, the “grind“ continues after the switch/change is complete.
- When the A/C toggle on the control switch is toggled off. The noise goes away. Mode will still change without A/C on and without a grind.
- The grind accelerates with RPMs regardless of gear, including Park.
Question: is the ANYTHING inside the fire wall that changes with acceleration (less gauges)?
Question: What happens in the A/C system from the toggle on, when it’s toggled to A/C.
I know this is headed for taking the passenger seat out and sticking my big fat melon under the dash while some one drives - but I thought I might take a shot asking with more clarity.
I assumed it was an issue with the center blend/mode actuator or door, because it sounds like, maybe, nylon gears stripping. But, the noise accelerates with the engine. So how would acceleration relate to the actuator?
Any thoughts?
One more piece of information: The mode (?) doesn’t always change immediately. ( Mode is floor to dash to vent. Correct?).
Edit———————
- Changing the Mode is slow or delayed sometimes. Especially Dash Vents Only. However, the “grind“ continues after the switch/change is complete.
- When the A/C toggle on the control switch is toggled off. The noise goes away. Mode will still change without A/C on and without a grind.
- The grind accelerates with RPMs regardless of gear, including Park.
Question: is the ANYTHING inside the fire wall that changes with acceleration (less gauges)?
Question: What happens in the A/C system from the toggle on, when it’s toggled to A/C.
I know this is headed for taking the passenger seat out and sticking my big fat melon under the dash while some one drives - but I thought I might take a shot asking with more clarity.
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