Additional Alarm Components
The following components on the car are used in conjunction with the anti-theft device:
1. Door contacts
2. Trunk contacts 4-door
3. Tailgate contacts 5-door
4. Central locking system
5. Wiring runs for alarms 940 1993- and 960 1993-1994, and also for the control module item C/F for 960 1995-.
Door contacts
The doors have traditional built-in contacts in the A-posts or B-posts. When a door is opened, the contact is grounded. The door contacts send a signal to the central locking relay, the interior lighting, and the alarm control module.
Trunk lid contact 4-door
The trunk lid on the four-door model has a built-in contact in the locking mechanism. The contact goes to ground when the trunk is opened. The contact also governs the trunk lighting.
Tailgate contact 5-door
On the five-door model, there is a built-in contact next to the hinge on the left hand side. The contact has the same function as on the four-door model.
Central locking with the basic alarm (4)
The central locking motor in the driver's door has an integrated two-position operating switch which sends grounding signals to the central locking relay.
The driver's door also has a micro-switch (AT-switch) mounted on the lock cylinder. Its purpose is to send a control signal to the central locking relay before the central locking setting device is affected by the door key, whereupon the relay sends out signals to the alarm control module to activate or deactivate.
When the central locking remote is operated, a code is detected by the sensor unit, which sends signals to the central locking relay, which in turn sends signals to the alarm for activation or deactivation.
Central locking with Guard Alarm II (4)
With this alarm the situation is reversed: i.e. it is the alarm control unit which receives the radio code and which in turn sends signals to the central locking relay for locking or unlocking.
The wiring
The wiring runs from the above components to the alarm control module. The wiring is also connected to the start inhibitor, the turn signals, the horn and the alarm's indicator LED.