BMW 3 series E30

Since 1983-1994 of release

Repair and car operation

+ 1. The maintenance instruction
+ 2. Maintenance service
+ 3. The engine
+ 4. Cooling system
+ 5. Heating and ventilation
+ 6. Fuel system
+ 7. An exhaust system
+ 8. Transmissions
+ 9. Coupling
+ 10. Brake system
+ 11. A running gear
+ 12. A body
- 13. An electric equipment
   13.1.2. Search of malfunctions
   13.1.3. Safety locks
   13.1.4. The relay
   13.1.5. The breaker of indexes of turn / of the alarm system
   13.1.6. Switches on a steering column
   13.1.7. The ignition lock
   13.1.8. The receiver
   13.1.9. The aerial
   13.1.10. A guard of devices
   13.1.11. Payment SI (the maintenance service index)
   13.1.12. Headlights – replacement of lamps
   13.1.13. Adjustment of headlights
   13.1.14. The headlight case
   13.1.15. Replacement of lamps
   13.1.16. The screen wiper electric motor
   13.1.17. A heater of back glass
   13.1.18. Safety pillows
   13.1.19. Cruise-control system
   13.1.20. The central locking system
   13.1.21. Electric стелокподъемники
   + 13.2. Electroschemes
+ 14. A good advice

13.1.2. Search of malfunctions

The structure of electric chains of the car includes the consumer, switches, the relay and the wires connected under the applied scheme. Before starting troubleshooting it is necessary to study the scheme and to define a possible source of malfunction. For example, the troubleshooting problem is considerably facilitated, if it will be possible to check up serviceability of other consumers expressly or by implication connected to the suspected chain.

If refusal of several consumers most a plausible reason is breakage of connection with weight or перегорание a safety lock is observed. As a rule electric equipment refusals are caused by easing of contacts or their corrosion, перегоранием a safety lock or оплавлением crosspieces. Search of malfunctions as a rule is carried out by means of a tester (voltmeter) or a control lamp which are connected between a 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 a 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), connection with weight the reliable. Otherwise contact to weight is broken. Keep in mind that in most cases the weight serves the return токопроводом, connecting a chain with a negative pole of the battery. Therefore infringement of connection with weight, or rupture in a chain of a return current on the battery, can be a refusal principal cause.

The prevention

The part of cars is equipped by safety pillows (so-called SRS-system of additional safety). Works on electric equipment repair in salon on these cars should be carried out only in car-care centre.