04 mazda 6, factory alarm goes off

I installed a remote start in my son's 2004 Mazda 6 a couple months ago. Has been working fine up until a problem today. And not sure that it is related or not. This morning the factory alarm went off when he opened the door. He opened the hood looking for a fuse to pull. It timed out but when he shuts the hood it starts blowing the horn again. I've heard of factory hood switch problems, but it seems more as though the remote start isn't disarming the factory alarm. One other piece of information; his factory remote stopped working about 2 weeks after the RS install. I'm suspecting battery because he hasn't tried replacing it. Any experience out there with this issue? Thanks, Todd

Kind of difficult to diagnose this over the internet, but start with replacing the factory remote battery. If it still disarms the alarm correctly, the issue is probably in the remote start installation. Could be as simmple as a bypass needing reset or a loose wire, or even a dead brain unit not sending signals anymore.To master and control electricity is perfection. *evil laugh*

How are you locking the vehicle? Key in the door, door lock switch ? Aftermarket remote? By putting the key i n the door and turning it to unlock, will that disarm it?Advanced

Thanks for the ideas guys. I'll do some checking when I have the car here. To answer dasbogie: yes, aftermarket remote start and that is used to lock/unlock. Will have to test the key in door.