Car Alarms: 91 suburban alarm, override switch, manual override

Question
my alarm went off and now truck wont start.also i don't have the remote. thanks

Answer
The 91 Suburban did not come with a factory antitheft system.  This leads me to believe your system is aftermarket.  Most aftermarket systems have a manual override switch, typically mounted on the driver's side of the vehicle.  To activate most of them you would turn the ignition key to the run position and push/flip the switch.  This would cause the LED indicator to illuminate solid and disable all security features of the alarm.  If you want to find a replacement remote for the system, take a look under the driver's side dash and trace back the wiring to the brain of the system.  On the brain itself would be a make and model number, post that information back on here and I will see what I can find on both a replacement remote as well as manuals for the system.  If you just want to remove it all together, here is basic instructions on how to do that:

Typically an alarm system would be installed on the driver's side interior of the vehicle.  This system would have been tapped into the ignition switch wiring running down from the key.  If you remove the dash panel(s) under the steering column you should be able to locate where the harness was added that goes to the alarm.  Disconnect each wire that was tapped in and insulate the factory wiring.  You will also see that at least one of the wires was cut, this is the vehicle starter wire that runs from the key to the starter.  This wire needs to be restored, I always recommend soldering all connections but crimp connectors should also work.  Make sure that you remove all connections to the alarm and that any wires that may be exposed are insulated and mounted in a way that they will not interfere with any moving parts and do not run the risk of shorting out.  Remember to take your time and follow each connection running from the brain of the system, leaving one wire connected that you are unsure of the function could cause problems in the future so be sure to remove every wire.

Hope this helps.