Bulvot

It's always bothered me that the 928 doesn't have a proper HVAC recirculation button/mode. There are certain modes of operation that cause the recirculation flap to close, but you can't independently close/open it whenever you want. Sometimes, I just want to have fresh air blowing into the cabin without having the HVAC system on. And sometimes I want the AC to be recirculating without having the temperature slider in the coldest position. Or, just going into recirculation mode when in traffic behind someone who's smoking. There are a lot of reasons to be able to control that setting manually.

What I did was cut the recirculation vacuum solenoid control wire (blue) at the 15-pin plug that plugs into the back of the HVAC control unit in the center dash console. Then extend the blue wire from the solenoid to a switch mounted on the right side of the driver’s parcel tray. The ground and ignition switched power that feeds the 15 pin connector has been tapped and extended to the same switch in the driver’s side parcel tray. The switch provides manual control of the recirculation flap. The switch has a blue LED that is on when the recirculation solenoid is energized, which places the HVAC system into recirculation mode (closes the flap). I used a screw on barrel connector for this new electrical connection to facilitate easy removal of the switch. The mount itself is flat steel bent into a u-shape that slips over the vertical side end of the parcel tray and is easily removed.

Reversal involves reconnecting the blue wire. Easily done if needed. The barrel connector makes it easy to disconnect whenever I need to remove the parcel tray.

Now, as long as the ignition is on, I can control whether or not the flap is closed. I thought about a three position switch so that I could still have the HVAC head unit control the flap sometimes, but I doubt that I would ever use that setting. It's not reachable by the passenger, but easy to reach and see for the driver. The blue light gives a quick visual tell, and the recirculation sticker indicates what it does. It would be easy to turn it into a center console push button, but I didn't want to add any holes to my dash. I like things to be reversible if I change my mind.

After this picture was taken, I repositioned the sticker so that it's perfectly horizontal:


Just an idea for someone else with a similar need.