My right hand is SO COLD

[Brewmaster]

And it's impeding my shifting. Are the center registers supposed to blow outside air, regardless of situation? If so, does anyone know of a modification to change this? If not, what should I check to see where the problem is? I'm tired of hot/cold/hot/cold

[nuclear944]

The center vents shouldn't blow outside (cold) air if the air distribution control is set to a position higher than 9 o clock. Additionally, there is insulation between the vents and the duct on the right side of the radio which can degrade and cause cold air to leak even if the center vent switch is off.

[drwatson32]

Quick mod: press recirc button

[drwatson32]

Agreed. I spend entirely too much time behind the wheel and it has definitely helped to stay awake in the winter.

[peva]

The centre vents will blow cold unheated air whenever the air distribution knob points to a symbol with a square combined in the symbol as shown below In the early days of the 900 this square was actually coloured blue indicating fresh air. All vents apart from the centre fresh air vents are heated air controlled by the temp knob. I've never found it a problem once you realise what you're dealing with.

[SmaartAasSaabr]

Or turn the little slider knob to "0"!

But even with this - my right hand freezes and my left hand gets 3rd degree burns on a long drive.

The C900 HVAC is really annoying in this way and also the nature of the valve-based heater core making adjustments difficult. You always have to twist the knob hot and then colder but then you wear out the valve and need to replace :p

at least the distribution knob is vacuum so it sometimes fucks up, but the NG 900 / OG 9-3 has a plastic arm and it just snaps right off...