99 Tahoe vent selection switch

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Eman85

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Are you meaning the mode or position selection? The controls are all electric and doors are moved using motors. Position control is a motor and levers on the left side of the unit right above the gas pedal.
 

YukonGTmaster

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I had the same issue as you on my 97 Yukon. As @Eman85 said, check blend door actuator under driver's side dash. One of the "Arms" on my actuator had broken, and was just hanging there. When you select the different position on the control panel, you should hear the electric motors running. If more troubleshooting is required, I would look at the main connector behind the climate control panel at the dash. I had a badly melted connector, that was limiting my fan speed selections. Good luck!
 
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Rick_Grff

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Thank you for your responses. Nothing happens when I turn the motion switch its stuck at the bottom vent. The arms don't seem to be broke. I'll start with the switch. Does the front of the dash need to come out???? To get to the switch. Thanks
 

east302

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The actuator has a notched silver position dial. Does it turn smoothly when the dash dial is adjusted?

If motion is jerky, not through the full range or if it makes a gravel or ratcheting sound, the gears inside are likely broken. Ignition off, remove the actuator and verify that the three dampers move. If they do, you can open the actuator up to check the gears, but it’s probably shot.

If no movement (or sound) at all from the actuator, disconnect the wiring connector and it should have three wires. I forget the colors, but one is battery voltage, one ground and the other the signal from the panel which varies (I think 1 to 5V?) based on dial position. Check all three for voltage/ground. If no signal from the panel and no wiring damage, the panel would then be the culprit.

If electrical checks out, verify damper movement and actuator gear condition.

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YukonGTmaster

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Thank you for your responses. Nothing happens when I turn the motion switch its stuck at the bottom vent. The arms don't seem to be broke. I'll start with the switch. Does the front of the dash need to come out???? To get to the switch. Thanks
Check out this video.

 
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