E30 series BMW 3

since 1983-1994 of release

Repair and car operation

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

If refusal of several consumers is observed, the most probable cause is break of connection with weight or a safety lock peregoraniye. As a rule refusals of electric equipment are caused by weakening of contacts or their corrosion, a peregoraniye of a safety lock or a crossing point oplavleniye. 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 tokoprovody, connecting a chain with a negative pole of the battery. Therefore violation of connection with weight, or a gap in a chain of a return current on the battery, can be the main reason for refusal.

The part of cars is equipped with safety cushions (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 center.