i work at autozone and i see this quit regularly, a failing key fob battery will cause it to go off to, one guy said his truck would start on its own. when we replaced his battery the truck started but he was able to turn it off and on with the remote afterwards. said he hasn't had anymore trouble out of it. autozone has a tester on the counter to see if your battery is ok.if thats not the case ask the dealer.

 

I had this same exact problem in my 2000 blazer, but I knew it coincided with the fact that the gate light in the gauges would come on randomly. after about 8 months I finally found out that I had a pinched wire in the rear door seal where it clips in under the tale gate no more problem.

the symptoms: the gate light came off and on randomly driving or not so when the truck was locked if the light suddenly came on making the truck think it was broken into so it would set off the alarm.

most likely the same idea happened when you got new speakers put in if the problems coincide. pull of the door panel and check the wires for torn insulation and tape them up. that is if it is not the remote.