Dash Knocking | AC & Heat do not work | Help

[Colton2010 SLT]

Hello, when I first start my 2010 Ram 1500 SLT (whether the ac or heat is on or off) it starts making a sporadic knocking noise coming from the lower part of the dash in the middle (where I believe the air door actuator is). If I keep the air off or turn on heat the noise goes away after a minute or so, however no heat will come out. Some air does, but not very much and its not warm. If I turn the ac on it starts knocking again. When the heat is on and I turn the fan all the way up it makes kind of a buzzing noise which basically sounds like something is broken or just not quite working right. Is this the air door actuator? It just seems like it may be a little more than just that. Thanks!

 

[Colton2010 SLT]

Bump: Also, no matter what air setting you put it on (feet, windshield, lutiple vents etc.) It blows out of every vent.

 

[White02]

I have a 2002. I have replaced the actuators 2 or 3 times. Used OEM parts and they don’t last 6 months. My A/C and heater do not work right and they make the same noise you refer to. It’s too expensive to keep replacing actuators.


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[Fast69Mopar]

Hello, when I first start my 2010 Ram 1500 SLT (whether the ac or heat is on or off) it starts making a sporadic knocking noise coming from the lower part of the dash in the middle (where I believe the air door actuator is). If I keep the air off or turn on heat the noise goes away after a minute or so, however no heat will come out. Some air does, but not very much and its not warm. If I turn the ac on it starts knocking again. When the heat is on and I turn the fan all the way up it makes kind of a buzzing noise which basically sounds like something is broken or just not quite working right. Is this the air door actuator? It just seems like it may be a little more than just that. Thanks!

What you are hearing is likely a damaged mode door actuator or a broken mode door. The mode door controls where the air is distributed throughout the ducts and into the cab. The clicking sound comes from either inside the actuator because the gears are stripped internally or the splines have become stripped off where the actuator attaches into the door itself.

You can verify this by removing the actuator and looking at the splines. Once you have removed the actuator, operate the mode knob on the HVAC Control Head to see if the actuator turns and to verify it is making noise. You can also operate the door by hand to see if the door moves inside the housing. If the door is damaged/broken you will feel the female end spinning where the actuator attaches.

If you do not feel the mode door moving inside the housing while turning the door then it is time to remove the instrument panel and the HVAC housing for further inspection.