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BMW 3 Series E30since 1983-1994 releaseRepair and operation of the car |
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BMW E30 + 1. Maintenance instruction + 2. Maintenance + 3. Engine + 4. Cooling system + 5. Heating and ventilation + 6. Fuel system + 7. Exhaust system + 8. Transmissions + 9. Coupling + 10. Brake system + 11. Running gear + 12. Body - 13. Electric equipment 13.1.2. Search of malfunctions 13.1.3. Safety locks 13.1.4. Relay 13.1.5. Breaker of indexes of turn/alarm system 13.1.6. Switches on a steering column 13.1.7. Ignition lock 13.1.8. Receiver 13.1.9. Antenna 13.1.10. Guard of devices 13.1.11. Payment SI (index of maintenance) 13.1.12. Headlights – replacement of lamps 13.1.13. Adjustment of headlights 13.1.14. Headlight case 13.1.15. Replacement of lamps 13.1.16. Screen wiper electric motor 13.1.17. Heater of back glass 13.1.18. Safety cushions 13.1.19. System cruise control 13.1.20. The central locking system 13.1.21. Electric stelokpodjemnik + 13.2. Electrical circuitries + 14. Useful tips |
13.1.2. Search of malfunctions
The consumer, switches, relay and wires connected according to the enclosed scheme are a part of electric chains of the car. Before starting troubleshooting it is necessary to study the scheme and to define a possible source of malfunction. For example, problem of troubleshooting is considerably facilitated if it is possible to check serviceability of other consumers directly or indirectly connected to the suspected chain. If the refusal of several consumers is observed, then the break of connection with weight or burn-out of a safety lock is the most probable cause. As a rule failures of electric equipment are caused by weakening of contacts or their corrosion, burn-out of a safety lock or an oplavleniye of a crossing point. Search of malfunctions as a rule is carried out by means of a tester (voltmeter) or a control lamp which are connected between the site of a faulty chain and well smoothed out site of weight. For check of reliability of connection with weight connect through an ohmmeter (or through a control lamp to the battery) checked connection of a wire with weight and well smoothed out site of weight. If the ohmmeter shows a chain (or the lamp will light up), then connection with weight reliable. Otherwise the contact with weight is broken. Keep in mind that in most cases weight serves as the return current distributor connecting a chain to a negative pole of the battery. Therefore violation of connection with weight, or a gap in a chain of the return current on the battery, can be the main reason for refusal. Prevention
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