Originally posted by clickwir
So I could just put a switch inline with the dimmer line and turn it on and off at will?
If you're really adamant about adjusting the brightness of your clock, sure.
Originally posted by clickwir
Now... to get back there..... 
h:
What would the accessory one be for?
To turn it on when you start your car..... the constant 12+ is for memory (to keep the time when your car is off), acc. is to turn it on when you start the car.