Security Tips
Rather than spending money on an alarm, try this: Ever driven down the road with only open headers? You get noticed, huh? If its that loud then it will attract the cops. Mr Gasket sells a tailpipe "valve" that lets you swap between your regular exhaust and open headers. You can simply switch to the open position when you leave your truck for the night, and if a would be thief starts the truck, it's a regular alarm.
The advantage to this system is you don't have to cut anything. Just add another wire to the coil post. The disadvantage is that all you have to do to disable it is remove the extra wire from the coil post.
Also, my older alarm came with a programmable siren sound, so I programmed in a series of dots and dashes; I spelled out S-O-S. I can tell if the siren is off my alarm or just a generic siren sound... plus it also has an extra output for airhorns.
Finally, there's a new device that looks like the club, but it gives a non- lethal shock to the intruder.
The best system is one of the satelite tracking systems such as LoJack in your area. That way if they do steal it, you have a good chance of recovering it. As for cutoffs, the Jacobs ignition system has a cutoff that allows someone to start the vehicle, but if they don't push the reset button (which you hide), the vehicle will die a few minutes later and it won't restart (even if they do find the button and push it) for several more minutes. No thief will hang around that long, especially since it probably died in traffic.
Also, I always park such that the car would have to be dragged onto a trailer (as opposed to lifting the back and rolling it out). If you can't do that, park with your wheels turned. That will make it a little harder to tow or get the car onto a trailer.
Why not put a dead fuse in the ignition slot of the fuseblock? Just swap it out when you park. I don't think thieves check fuses. They would assume there is a switch and start looking.
I figure if someone has spent enough time stealing vehicles they should have a clue as to where these batteries are kept, or keep a sledgehammer handy to obliterate the siren the moment they pop the hood.
Some pros use ultra-heavy-duty zip ties and attach the brain directly to the wiring harness above the column. That way if a thief tries to rip it out, they destroy the wires with it, although fixing such a car could prove a nightmare. Mount the siren behind the front grill so that the grill must be removed for access. An alarm with airhorn outputs is also a good idea, adding an extra form of back up and generating more interest than an alarm. Run all wires inside the engine compartment by taping them to the existing wiring harness along the entire length so they cannot be identified.
Most alarms disable when the siren and power wires are cut or grounded. Do not wire the alarm to the battery as instructed. Wire it to the hot leads from the battery on the OEM harness inside the cab and way up behind the dash. Install a backup battery as extra insurance. I do not know where you are, but in many bigger cities you can get a transponder installed that pages a central dispatch center in case of trouble. The exact location of you vehicle is displayed on a street map in real time so the police can be dispatched to the exact location of your vehicle. (all for a nominal monthly fee of course). Check your bigger auto electronics and cellular systems dealers for this system.
I also recall the words of wisdom thieves left a young man after they stole two Corvettes from him and in desperation he chained the third to a light post. He came home to find the car turned in the opposite direction to which he had left it but still chained to the post. The note read "if we wanted this one, we would have took it also"