99 security system won't shut off

99 S-10 Blazer having an issue with the horn / security system going off when the truck is sitting in parking lot. Basically the alarm will go off ocassionally for no apparent reason. the key fob will not shut off. they only way to stop is by putting the key in the ignition and cylcling the ignition. little bit of a pain at the wee hours of the AM...okay anytime. seems to be worse when the vehicle is left locked. Anyone else have the same problem?? Any Ideas on what is wrong or how to by-pass?? Doesn't have an issue starting up and running.

99 S-10 Blazer having an issue with the horn / security system going off when the truck is sitting in parking lot. Basically the alarm will go off ocassionally for no apparent reason. the key fob will not shut off. they only way to stop is by putting the key in the ignition and cylcling the ignition. little bit of a pain at the wee hours of the AM...okay anytime. seems to be worse when the vehicle is left locked. Anyone else have the same problem?? Any Ideas on what is wrong or how to by-pass?? Doesn't have an issue starting up and running.

Factory or add on stuff?
If factory a good body capable scanner should show problem.
Any body codes?

Yes it is the factory alarm system

Yes it is the factory alarm system

Need to be put on a body computer capable scanner tro see what is going on.