2000 Bravada Security System Questions

[matt_o_70]

looking for some help.

 

I have a 2000 bravada that I purchased used, previous owner installed an aftermarket alarm & remote starter (code alarm 645).

 

I would like to completely remove the aftermarket alarm, since the car has factory security system, But It seems that when they installed the aftermarket alarm they somehow cut into the factory key recognition system. When I have unplugged the code alarm system the truck cranks but will not run, What I have read lead me to believe the factory system disables the fuel pump. I have read that there is a resistence value and small wires that are part of this system that the aftermarket alarms must work with. It seems that when the aftermarket system is removed the ciruit needed for the factory system now needs to be restored?

 

How does the factory system work? I have had to wait for the system to "accept" a key before the truck will start (after playing with the alarm)?

 

I would like to be able to restore it to the original but need to know how the oem system works.

 

sometimes the oem "security" indicator on the dash stays illuminated after the doors have been locked? Some times this light will flash, I was of the impression that it flashes only when not locked to remind you to lock the vehicle?

 

Matt

[minibike132]

The system works like this, There is a pass lock sensor that is part of your cylinder, it has 3 wires going to it from the BCM, a 12 volt reference, ground and passlock sensor signal. The BCM supplies power and ground and when you stick your key and turn the cylinder an analog signal is produced by the cylinder and passed back through the passlock sensor signal back to the BCM. Usually remote starts have a circuit to fake this signal but you said alarm not remote start, I can't really think of why an alarm would be wired in to this circuit. None the less the 3 wires come down the collum and go into that big connector down there at the bottom (c211). The 3 wire colors your looking for are Red with white tracer, orange with black tracer and Yellow. All 3 are the same size and fairly thin. Take a look and see if there is anything left over from removal or if any wires are dammaged first thing. Also when they leave that connector they go to the bcm so you could have a problem anywhere on those lines but alarm companies like to stick to the area between the collum and c211. Give it a look and check back.