silverscoob785

Hi everyone I've recently bought a modified 2003 silver wrx, been having some issues with the fob/alarm system Essentially the car won't start anymore. The fob unlocks the car fine and the red light on the boost gauge stays red, but the red key on the dashboard stays flashing so when you try to start the car it sets the alarm off. I've changed the batteries in both fobs with no luck. I've also disconnected the battery and reconnected hoping that would reset the system, only change now is the red light flashes rapidly. As far as I can see the fob disarms the car fine, but then as soon as you try and start it, the alarm goes off. I don't think its key related as I've changed the battery in both keys. One thing to note is the other day I locked it and then the alarm went off for no reason, only happened once but I assume 20+ year old electronics is to blame. I want to try and sort it without having to call a mechanic out but this is my first proper modified car so am a bit baffled at the moment Any suggestions?