what's the blinking LED?
 

Troubleshooting a short that discharges battery in just a few days. I've eliminated most possibilities but what is the blinking LED under the dash, at your left knee, just above the hood latch? 2 blinks, pause, 2 blinks, pause . . . all the time. 2008 Shelby GT so this could be a Ford LED or something Shelby added. Anybody know what it is?

Do you have an aftermarket alarm installed that you don't know about?

Actually, the 05-09 models came with a dealer installed alarm system that is Ford brand. The LED belongs to it. Depending on the dealer, the led is installed above the left or right knee.

the alarm module itself can be stashed in one of several locations depending on the dealer. Just follow the wires from the led.