2005 Silverado 5.3L Outside Air

[Gito]

Friend just bought a 2005 Chevy Silverado 5.3L (LT) Crew Cab.
He's complaining that he cant keep the outside air from coming inside the truck (cabin).
Is this normal?
Is there anything that can be done to completely seal off the outside air?

I could of sworn that I once read that a certain amount of outside air is supposed to always come in.
My friend thinks that too much outside air is making its way inside.


Any advice is greatly appreciated

 

[Chris142]

Should be a button on the dash that shuts the recirc door. If it doesn't it likely has a bad motor.

 

[Snagglefoot]

There should be a recirculate function and perhaps a way of shutting off the fan entirely. What is he getting at, pollen or something regarding allergies?

 

[spasm3]

recirc does not work on mine if defrost is selected.

 

[Skippy722]

Both our old 2004 1500 and the my old shops 2003 1500 HD would both allow air through the HVAC system no matter what setting it was on. It was only when you were moving though. At 60mph in the winter it would roast you with the fan off if you left the temp set to hot after about 20 minutes of driving.

That's a nice truck btw. I really want another one! Ours met an unfortunate and early end back in 2015...

 

[Tomioka]

Normal for my 02. It resets to fresh air after engine start. Always have to hit the recirc button (fan off or A/C kicks on) before taking off since it's been getting colder.

 

[TurboTravis]

I own the same vehicle and experienced a similar problem over the summer. My first course of action was to verify that the blend door was not moving when it was supposed to be (when going from fresh air to recirc and back, etc). It was not moving, so I replaced the blend door actuator, which is not the easiest task to say the least. Long story short, it was not the actuator. I later learned that there is a TSB to reprogram the HVAC system to deal with this. I did not want to mess with it anymore, so I disconnected the plug from the actuator and manually moved it to recirc. Your friend could also try resetting the system by pulling the fuse, but that probably will not help.

 

[TurboTravis]

TSB http://ww2.justanswer.com/uploads/DBAutomotive/2011-08-26_205636_05_gmc_air_condi.pdf

 

[DriveHard]

If it is like the NBS Silverados, there are huge vents to the outside behind the rear seat below the window on each side. Blocking those would reduce the amount of air entering through the HVAC system...but also makes it more difficult to shut the doors ;-)

 

[KalapanaBlack]

I know the 1990s GMs I have experience with, unlike the Japanese cars I've owned, simply did not seal off the outside on recirc. Most foreign cars seem to almost hermetically seal, while GM seems to have decided years ago that "recirc" meant 60/40% split between inside and outside.