hood pin switch ford f150 oem alarm

I have a 2006 Ford F150 that has the factory alarm. I added a tool box to the truck, and I am wanting to put a hood pin switch on the box, so that when someone opens the lid, the pin switch will ground and cause the alarm to go off. Where would I tie this into? Thanks.

It would make sense that you can tie into one of the door triggers and diode isolate the pin switch. However I'm not finding anything from Directechs.com that indicates a 2006 F150 would have an alarm. If you lock the doors with the window down, wait 60 seconds and then reach in and manually open the door does the horn start to honk?

I actually had to check. I just bought the truck and was not sure. I rolled down the window and locked the doors with the key fob, and waited about 2 or 3 minutes. I opened the door from the inside, and it did not set off the horn honking. I guess it is just keyless entry with a panic button. Oh well. I guess I will need to install an aftermarket alarm. I was trying to get away from doing that if I could.