This morning my truck was warming up, when I went out to leave I noticed a blinking light that is visible through the bottom of the windshield where the VIN number is. Anyone have any idea what this light is?
2013 Screw with 5.0 and no mods yet. Also, there are no lights blinking in the cluster and last I checked I have no error codes being logged.

 

Only thing I can think of is the 'alarm' light (I forget what it's called.)

 

Is this a truck you bought used?

I have a 2013 XLT and I have no light there.

HOWEVER, I also installed myself the VSS (Vehicle Security System), which is a motion sensor that CAN include an optional blinking red led. Very small. It has a recommended installation point, but of course it can be installed anywhere. Does your truck have VSS? If you don't know, open the driver's window, then close the door. Walk to the front and look at the light. It should be OFF. Now lock the vehicle with your remote.

The light should be solid for 20 seconds, then begin to flash a steady on/off sequence every 3 to 4 seconds.

Using your closed fist, impact the steering wheel with moderate force. The horn should honk and the lights flash one time.

Using your closed fist, impact the steering wheel with heavy force. The horn will honk and the lights flash repeatedly.

 

Yes I bought the truck used, I thought security light too, but I just checked and now that the truck has been off for a bit, the light is off. Note that the light is back under the dash, where I think security lights are usually more visible on the dash. This light would not be visible really unless you were approaching at just the right angle. Was hoping it might help me in diagnosing the occasional battery drain I am having, but since it is off when the truck is off probably not I guess.