2000 chevy Impalla remote start

I'm hooking a remote starter up in this car.  I have it all hooked up and now it won't even turn over.  I tested the volts on the battery and it runs right around 12.  I just can't figure out what would cause this.  Does the factory alarm have a starter kill and if so how do I get it to turn off.  When the ignition is on the message center flashes back and forth between the battery light and saying "security system". 

Sounds like a dead battery to me (Charge)Lloyd

It won't even start with the key. That's what is confusing me.  I wouldn't think the brown wire would matter if starting with the key.  I can't see why the battery would be dead it was unhooked almost he whole time.

I have had a lot of trouble with dead batterys when installing RS's & allways keep a spare handy ????Lloyd

since it hasn't been mentioned here yet this vehicle has the Passlock II immobilizer which needs bypassed for remote start. If you don't bypass it, and attempt to remote start the vehicle 3 times I think, the vehicle will go into long tamper mode and won't start(with the key or the r/s) for like an hour or two. As Jeff said earlier, this vehicle also has 2 ignition and 2 accessory wires that all need powered up.

keep in mind too that the passlock bypass controls the starter not a fuel shutoff, so if you have a dud bypass module that interupts the passlock circuit then the vehicle wont even crank with the key.......Kevin Gerry

Certified Electronics Technician

MECP First Class Installer

Owner/Installer

Classic Car Audio

since 1979

It ended up being the bypass module.  Thanks everyone for the help. 

My RS only has one acc. wire. I need to power up 2  I diode isolated both and tapped them into my RS  acc wire is that the right way.