grand cherokee alarm system gone rong?

i have a p reg cherokee, i'v tried manualy disarming the alarm by opening the drivers door and tailgate, my remote keypad sensor has no effect. The engine won't turn over teh intirior lights stay on even when doors are shut. I'd like to know how to bypass or dismantle the alarm, but can't find any of the cmponants. Any help would be much appriciated