Pontiac g5 pursuit issue

[Amart88]

I do not know if this is in the right place or not..

Got a 2006 pontiac g5 pusuit, I upgraded my electrical a few months ago, 270 amp alt, BIG 3/w 0 gauge and everything works fine until one morning I pull into work around 6 am, I turn my lights out and shut the car off but soon as i took the key out of the Ignition the headlights started making short flashes along with short honks from the horn... a few seconds later the horn goes full blast car alarm on me with the lights still flashing , the only way i could stop it was to start the car or disconnect the battery.This was very embarrasing that early in the morning. The car has no aftermarket alarm at the moment and has just power locks, trunk pop and that red panic button via key remote. It did not do this everytime only somtimes. So the next day at home i slid my keys across my dresser and to my suprise the car starts its routine again... so i removed the batterys from the key remotes and it hasn't done it since... No garage to this date or GM themselves could tell me whats wrong (typical).

So i figured I would ask you guys on here if you ever experienced something like this??? My guess obviously is faulty remotes but they never did this before my upgrades. I still don't use them to this date as im afraid the alarm will blare at 3 in the morning. any input is appreciated, Thanks

[BEEMDUB]

hmmm thats a crazy thing you got goin on there...I actually have heard of identical symptoms on the charger forums but 90% of the time it has to do with the canbus (computer) system and aftermarket or added on stock security system

[MIKE-2U]

Something to do with the Key fob ? a warning the batteries are low ?

Could have your dealer reset your remotes with the car. Aftermarket radio ?