Clicking noise behind rear seat where rear ac unit is

[ssbeast805]

Whats up fellas noob here to this forum,

Im having an issue right when i start the truck i hear a clicking noise for about 10 sec and it goes away. Its coming from the back of truck where the ac unit is. My question is have any of you ran into this issue and if so do you have a stsep by step to replace and P/N? Thanks for all your help

 

[Splatmaster527]

Are you sure its coming from the back of the truck?? Does the sound change with revs? The engines in our trucks are known to have a clicky tappy valve system at startup until they get oil up from the pump...

 

[ssbeast805]

Yeah im sure i had my wife turn on truck and i was back there and its a clicking noise for a few sec and then it stops. And i dont have any cold or hot air coming out of vents just the defroster vent works.

 

[TheYuk]

Mine has been doing this for years and does it all the time. It will do it one day all day then the next day nothing. I have no idea what it is though.

 

[chauncey0337]

Cargo area wheel well cover on passenger side??? Sounds like the blend door actuator for the rear ac/heat. I believe there's two actuators back there- one for hot/cold and one for upper/lower vents. I don't have any experience with the rear actuators but couldn't be much different than the front. I would take the cover off and try to see if you can tell which actuator is bad. I think the clicking noise is the stripped gears trying to move the blend door.

 

[ssbeast805]

Oh ok so question how the heck does that cover come off? Now would that be the reason I have no cold/hot air throughout Tahoe front and rear?

 

[chauncey0337]

Oh ok so question how the heck does that cover come off? Now would that be the reason I have no cold/hot air throughout Tahoe front and rear?

That cover should come off with just a few screws. Might have to remove C and D pillar trim pieces, not sure. So, are you saying you're not getting any HOT OR COLD air? Warm?

 

[ssbeast805]

Yeah nothing and if i try to turn on it only comes out through front defrost vents thats it

 

[chauncey0337]

Seems like you may have at least a couple of bad actuators which seems odd. 03 and up models use an upgraded electrical system and I'm not sure if the heating controls are tied into it, but you could possibly have BCM issues. Where is OMAR!

 

[ssbeast805]

Whats BCM? Sorry not familiar with that