No Alarm When Sensor Activated (Only Guard Alarm II)

Sensors are connected to Guard Alarm II's harness via the black 4-pole connector. The alarm is triggered when the lead at item 3 receives a ground signal. (which corresponds to item 5 on the control module 5-pole connector).


NOTE: If several sensors are connected investigate one at a time.


(Step E1) Checking the sensor ground lead




- Ignition off.




- Detach the black 4-pole connector to the sensor.




- Connect an ohmmeter between ground and the insulated base item 1.
The ohmmeter should show approx. 0 ohms.

If the reading is correct:
- Continue with step E2.

If the reading deviates:
There is a break in the ground lead between the sensor 4-pole connector item 1 and the control module's 5-pole connector item 3.
- Rectify the fault or renew the lead.

(Step E2) Checking the voltage teed to the sensor




- Ignition off.
- Connect a voltmeter between item 1 (ground) and item 2 on the black 4-pole connector.
The voltmeter should show battery voltage.

If the reading is correct:
- Continue with step E3.

If the reading deviates:
There is a break in the lead between the 4-pole connector item 2 and the 5-pole connector item 4 (situated on the top side of the alarm control module).
- Rectify the fault or renew the lead.

(Step E3) Checking the signal lead from the sensor




- Ignition off.




- Activate the alarm.





- Wait at least 10 seconds.




- Bridge items 1 and 3 on the black 4-pole connector.
The alarm should be triggered.




If the reading is correct:
There is a fault on the sensor or a break in the sensor leads.
- Check connections. Refer to Fault Alarm Wiring. Checking Leads and Connection

Rectify the fault or renew the sensor.
Replace the 4-pole connector.

If the reading deviates:
There is most likely a fault on the alarm control module.
- Follow the procedure given in Alarm Wiring. Fault Tracing Alarm Wiring