My son in law had been driving his 98 Trooper with a non factory key (no chip) I don't know how it even ran at all,.................but it ran bad, stalled all the time,and now will not crank at all (I'm told it is in theft mode) Now even with the correct key, it will not start. How do I reset the computer, or reset the alarm system? I'm told there is a valet switch (button) to bypass the system, but I'm unable to find it. Can anyone tell me the location of the switch, and what it looks like? Please.

Cars & Trucks - Isuzu - Trooper - 1998 Isuzu Trooper