HOWTO: Integrating tilt sensor into existing alarm

[glenstewart]

I recently had my 1998 SL1's catalytic converter stolen while at work. The normal alarm system would not have stopped that, as the thieves simply jacked up one side of the car and sawed the cat out - there was no door entry.

Looking around at alarm systems, I came across the Audiovox CodeAlarm DUB1, which is a tilt sensor about the size of a USB flash drive. Crutchfield has it at one of the lowest prices. It claims to integrate with existing alarm systems, and also claims to trigger with just 1 degree of vehicle tilt after the system is armed - so I bought it.

After carefully studying the existing Saturn alarm, there is a way to integrate the DUB1 tilt sensor without cracking open the Alarm box, and without buying any additional relays or adapters. This article explains how. All photo references are from freegroupsDOTnetSLASHinnovativeSLASHglen_stewartSL ASHsaturn-alarm.
See picture P1040660.JPG

Other guides explain how to remove the rear seat and the passenger-side rear door jam trim, such as when installing new rear speakers. When doing so, the alarm control box is revealed, as shown in a photo further below.

You will notice that the alarm control box has a connector with lettered wire cavities. This guide shows the purpose and letter for each wire.
See picture P1040663.JPG
See picture saturn-alarm.png

Simply, you want to splice the DUB1 wiring as follows:

• DUB1 Green to Alarm White cavity K
• DUB1 Red to Alarm White cavity S
• DUB1 Black to Alarm Black cavity N

This photo shows the soldered connections.
See picture P1040664.JPG

The taped and secured complete system is shown below. Note that the DUB1 is placed under a seat in a flat position.
See picture P1040668.JPG

Other photos may be seen at the parent directory of the photos linked above. I'd place a link here, but the forum won't let me.

When the dome light switch is set to DOOR, and doors are shut with the alarm activated, the DUB1 will ground the door jamb circuit, simulating the door opening, and triggering the alarm. An artifact of this circuit setup, is that while the vehicle is in motion with the alarm off, the dome light will flash occasionally as the car goes over sloped or bumpy roads - so turn OFF the dome switch when travelling.

When the dome light is set to ON or OFF, the DUB1 will not be powered. This is a simple way to turn off the tilt sensor, if needed (like if the car is being transported by boat, or you live in a frequent quake zone).

The claims made by Audiovox about the DUB1 seem true. After installation and arming the system with the dome switch set to DOOR, I began to jack up one wheel. Before the wheel completely left the ground, the alarm went off.

I hope this gives a good starting point for others to do what I did, and hopefully improve on the interface.

Enjoy!

[glenstewart]

Over a year later, and the tilt sensor is still working perfectly exactly as it was installed. Enjoy!