I have a 2008 Taurus with a BRIGHT quick flashing ant-theft light blinking when ignition is off, and key is out. This problem started this a.m. Is there a process to clear this light. It is not in the handbook. Any thoughts?

 

I misread your post and need to send a correction

 

Thanks for getting back to me on this. I don't see any code, just a steady bright blinking ( brighter than normal). This started when I was replacing my headlight switch and had the door open and key in the off position. After about 3 min. there was a lot of mild beeping like an alarm. I have no alarm, except the stock passive alarm that is standard with this car. The car still runs fine, the light is off while it is running. The blinking only returns when the car is parked and engine is off. Weird

 

Now with the light partially on upstairs (in my head) lets look at what could be happening.
Could you without realizing it have moved a ground wire for the dash that the circuit might be using the anti theft system for a ground.?
The security system in your vehicle uses the instrument cluster to contain the functionality. Might be a good idea to recheck your work also If the switch was an aftermarket product , many times ford products seem to work much better with dealership supplied or genuine Motorcraft parts.Sounds crazy, but after getting burned a few times with offshore parts we get a little gun shy and from experience try to stay with OEM.

 

Thanks Hanky, I am using Ford parts and I rechecked the wires and anything that would make a ground and found all to be in order. The car is working OK for now, so I will have my mechanic put it on his machine next time I bring it in. Thanks for the assist.