17.3. Search of malfunctions - the general of data
The structure of electric chains of the car includes the consumer, switches, the relay and the wires connected on the enclosed scheme (see below). 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 weight.
Connecting a tester or a lamp consistently on a contour of a chain it is possible to reveal a faulty site which is found on loss of tension or a lamp pogasaniye.
3.1а Inclusion of safety locks of the assembly block
For search of short circuit in wires it is necessary to get a safety lock of a checked chain and in a gap to connect a lamp or the voltmeter. To short circuit with weight points lamp fire when rocking wires here and there (the tester should show tension). At check it is necessary to mean that some consumers receive a food at position of the ASS or Run ignition key.
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.