Checking the Power Supply

Checking The Power Supply





Unplug the connector:
- Siren, anti-theft alarm (275)





- Turn the ignition switch to the ON position.













- Connect test lamp 86 11 857 to pin 1 of the female connector and a good grounding point.





- The test lamp should light.

Checking the wiring harness
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.

Is the function correct?

NO - Rectifying the Lead

YES - Continue with Checking the power supply.













Take a resistance reading between

- 2 - Siren, anti-theft alarm
- 1 - Grounding point G30

The reading should be 0 Ohm - 1 Ohm

Checking the wiring harness
Jiggle the leads and in-line connectors at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.

Is the function correct?

NO - Rectifying the Lead

YES - Checking the Ground Lead For Shorting to B+