Checking the +15 Supply

Fault symptom
When activated, the alarm is not triggered when the ignition is switched on.
Fuse 19 blows.

Diagnostic procedure
1 Check that fuse 19 is intact and live with current.
2 Connect the Intelligent Saab Tester (ISAT) and select the "OBTAIN READOUTS" menu and then "IGNITION +15". Turn the ignition switch and read the display.
The ISAT should show "ON in the Drive and Start positions
3 Connect the BOB and check the voltage by taking a reading across pin 17 of the control module connector and a good grounding point while turning the ignition switch to the Drive and Start positions.
The voltage should be about 12 V.
4 Check the wiring for continuity/shorting by taking a reading across pin 17 of the control module connector and the output side of the fuse.
A resistance of < 1 ohm should be obtained.