harryg wrote:if there arent any wires how does it transmit the signal from the brake lights to this license plate frame thingy
Answer: A pendulem.
The unit detects when you you brake heavily. There is a very simple pendulum lever switch inside the unit. When braking force is applied to the unit, the lever swings over, closing an electrical circuit and activating the light flashing sequence. The lever is only activated by braking, not by acceleration, and doesn't seem to be affected by simple bumpy rough road movement either
It runs on lithium batteries for 2-3 yrs and depends on how much the light goes off.
When I was handling it during the installation it would go off. You can vaguely hear something on the frames right side but its not an obtrusive rattle while handling; but more like feeling it's movement. Also it lights initially, when I open the liftgate, but not usually therefter if I repeated again soon.
Also I use it as a back up system, it probably won't go off for a few weeks during my style of driving. It's basically a supplement to the main brakelight system and is there when I need it.
Modified by casperfun at 6:06 AM 3/26/2010