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 under the applied scheme (see more low). 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 weight.
Connecting a tester or a lamp consistently on a chain contour it is possible to reveal a faulty site which is found out on loss of pressure or погасанию lamps.
3.1а Inclusion of safety locks of the assembly block
For short circuit search in wires it is necessary to get a safety lock of a checked chain and in rupture to connect a lamp or the voltmeter. In short circuit with weight specifies lamp fire at rocking of wires here and there (the tester should show pressure). At check it is necessary to mean that some consumers receive a food at position of ignition key ASS or Run.
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.