My Boxster doesn't do this. You should go back and have the installer check all the wires. You can also read through the
Becker CDR220 thread under Installation notes. If you have a factory head unit, it's either the Becker 220 w/CD or a similar Becker model.
On the dimmer, I believe there are two settings for the dimmer level, one for normal display, and one for the headlights on. So turn on the headlights, then go to the dimmer menu and you can adjust the dimmer level. Then turn the headlights off and on, and you should see a difference. Mine was factory set with both settings at 100%.
-gbeck
#080000480
18GB Red, Waiting for Amber screen...