Ok. I was sitting at work today and my factory security went off. No one was near the vehicle when it went off.
Normally to disable the factory security I just place the key into the ignition barrel and turn it.


This time it did nothing. So I took the battery cable off, let it sit for 30 minutes. Hooked the battery cable back up and the factory security started to go off again.

Any tips?

And if no tips, anyone know where the horn is exactly on the f150, I will just snip it so I can work on the vehicle. I know the horn is just below the battery, but i dont see a way to access it.

 

I had the same problem as you with my '97. I think it has something to do with using keyless entry and using your key to unlock the door. Not for sure. But I have been using my remote only instead of using the keys to unlock the door. Haven't had it go off at all. The damn thing would go off for no reason. But even if I am right there at the door with key in hand I will use the remote instead.

 

Anyone know how to disable factory security with out pulling the fuse?