I am having a problem with my security and doorlocks. Last week it started with the doorlocks would not lock. This week my wife started to drive and the horn goes off and the interior lights start going on and off and blinkers also. I took all the door molding off and disconnected the doorlock mechanisms in the entry car and that didn't do anything. But I was looking in the book and it talks about the security module and I was just wondering if it is just a line replaceable unit. Any assistance would be greatly appreciated

 

I have 2002 Ford Explorer XLT.
I had the same problem, and It was the battery.

 

which battery the u change truck battery or remote battery