TD New Guy
Join Date: Jan 2005
Location: Central New Jersey
My Ride: 90 Daytona VNT
Engine: 153 ci
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Vehicle Theft Security System Module
I am having some issues with the factory alarm that is preventing my 1990 Daytona from starting.
The alarm has “woken” a couple of times in the last 20 years, but has been non-functioning for most of that time. It would never “arm” or even sound. A couple of times it lit “Alarm Set” light in the visual message center, but for most of the time it has been non-existent, a non factor. I always figured there was a problem with it, however as it never interfered with the functioning of the vehicle and I never appreciated the system, it was not something that I really cared about.
That changed recently. I jumped the ASD relay to drain the fuel tank in order to replace seals that had failed. The next time I connected the battery the headlights popped up, the parking and tail lights started flashing, and there was a ticking coming from the interior, behind the glove box. At this point, the fuel pump stopped working as well (I jumped the ASD and the pump would not turn, despite there being power at the pump).
I replaced the pump, changed the filter, and verified 55psi of fuel pressure at the rail. The pump primes when the ignition key is turned, and runs when the ASD is jumped.
However, from the moment I connect the battery the security module is ticking and flashing the lights, as though it’s been tripped. I have tried locking, and unlocking, both doors with no affect. I cannot get the alarm to turn off, and the car will crank, turn over, and immediately die. The SBEC is a Mopar Performance unit. I tried to start the car using two other SBECs I have, with the security module removed, with the same result.
I understand that the SBEC is looking for a signal from security module, via the BCM, to start the car, and that w/o that signal the car will not start. I visually inspected the security module PCB and there was no obvious evidence of damage.
I have the FSM including wiring diagram and I started probing the security module. There is no voltage from the driver’s door when the door is closed, and there is no voltage at the driver’s door ajar switch either. My initial thought is that the alarm will not recognize attempts to disarm it using door cylinder switches b/c it thinks the driver side door is ajar.
I realize this is an odd issue and I am in the position of fixing a system that was already broken. My goal is to get the security system working so I can remove it (while the vehicle is running) so all of my SBECs will no longer look for it.
As for questions, for those that have or are familiar with the system, is it normal for the security module to trigger when the battery is connected? I would like to determine if the security module is functioning as it should, or if this is an indicator that the module is broken, as that will inform my next steps.
I will admit that it is frustrating and almost unbelievable to be stymied by a 3o year old factory alarm that can’t be somehow bypassed or duped.
Thanks in advance for any feedback.