My 2005 OB has the single HVAC unit combined with the radio unit.

Last week I replaced a rear brake light and whether related or not, I since have an intermittent problem with the HVAC/radio controls.

First time, the digital display on the radio was unintelligible (only parts of numbers and letters) and the HVAC was unresponsive.

Restart had no effect. Finally turned the light switch on the stalk on and all worked as expected. Turned lights off and once again got the erratic behavior.

Yesterday, the controls were unresponsive on both the radio and hvac until I turned the lights on.

Turned car off and restarted and all worked as expected with or without lights.

Close encounters of the third kind??

 

I've heard that this is somewhat a common issues on these cars.  My ex's 06 Outback would occasionally have issues as well.

 

I would suggest searching over on the Legacy GT forums for a fix if you haven't already done so.

 

http://legacygt.com/forums/forumdisplay.php/interior-audio-22.html

I have a silver combined dash unit $40 + shipping from 80919 if you want it.