You sound very much like me; I park my truck ONLY where I can see it from my living room window. (Crappy aparment complex in a crappy neighborhood <img border="0" title="" alt="[Frown]" src="images/icons/frown.gif" /> )

Obviously, you want an alarm. Do you have about $300 to spend? That's how much a decent aftermarket alarm (Clifford/Viper/DEI) will set you back, installed.

Take it to a place that 100% guarantees their work (parts & labor) and let them disable the factory alarm and put an aftermarket in there.

Any Isuzu dealer will charge you at least $300 to replace your factory alarm (it sounds like it's bad...I doubt the ground wire is dirty...unless you've recently had the interior full of water and/or mud) and you'd be better served w/an aftermarket alarm with features like "warn away" where the alarm "chirps" when someone violates a pre-set perimeter around your vehicle. I have this on my Troop.

I could be sitting at the PC, typing a post (like I am now) and I'll hear "wheo-wwooop!" and I run to my living room window and throw the blinds open just in time to see someone parking next to me and getting out of their vehicle. They SEE me WATCHING, so they are extra carefull with their doors on that POS 1989 Ford Aerostar minivan they drive. You get the idea.

If the little punk criminals know that your alarm will alert if they even get NEAR your truck, they will leave it alone.

Sorry, I got OT here...look, it sounds like your alarm is toast. Forget factory, go aftermarket.