| 1. The usual electric chain consists of elements of the electric equipment, switches, the relay, engines, safety locks, fusible inserts and wires and sockets which connect all elements among themselves, the storage battery and in "weight" of the car. |
| 2. The cause of defect can be found much faster if to define, what of elements of this chain work normally. If some elements or chains fail at once, the problem, possibly, consists in the fused safety lock or bad grounding as frequently one safety lock protects some chains. |
| 3. Problems with work of system of an electric equipment are usually caused by the simple reasons, such as the oxidised or unreliable contacts, the fused safety lock, the fused fusible insert or the faulty relay. Visually check up a condition of all safety locks, wires and sockets in a faulty chain before the beginning of check of other elements of this chain. |
4. The basic devices necessary for failure detection in a chain are:
– A tester or the voltmeter (or a bulb on 12 In with connecting wires);
– A control bulb with the power supply (or the device for check of integrity of chains);
– An ohmmeter (for resistance measurement);
– The storage battery;
– щупы with wires;
– накидной a wire, it is desirable with the automatic switch or a safety lock which can be used for check of wires or elements of the electric equipment. |
| 5. For detection of unreliable connection or a short circuit place (usually because of the bad either polluted connection, or the damaged isolation) it is possible to shake wires by a hand to see, whether there is a chain out of operation at wire movement. Such by it is possible to find a point with an unreliable socket or a point in which there is a short circuit. |
| 6. Besides the problems connected with unreliable connection, the electric chain can have two others the basic malfunctions – breakage presence in a chain or short circuit. |
| 7. Breakage in a chain can be caused rupture of any wire or absence of connection in a chain that will prevent a current current. Breakage in a chain will cause failure of any element of the electric equipment, but will not lead перегоранию the safety lock protecting this chain. |
| 8. The malfunctions connected with short circuit, are caused by short circuit in a chain that leads to that the current flowing on a chain, starts to flow on other chain, and leaves on "weight" more often. Short circuit is usually caused by isolation rupture that allows a feeding wire to concern either other wire, or the earthed element, such as a body. Short circuit leads перегоранию the safety lock protecting the corresponding chain. |
| 9. Before search of a source of malfunction or at repair carrying out in system of the electric equipment, keep in mind, that various types of wires have various colour. |
| 10. For detection of rupture of a chain connect one of щупов a control bulb to the negative plug of the accumulator or "weight" of the car. |
| 11. Connect the second щуп to connection in a checked chain, it is desirable located as it is possible more close to the storage battery or a safety lock. |
| 12. Submit pressure on a chain. Do not forget, that in some chains pressure moves only at key turn in the ignition lock in certain position. |
| 13. If pressure is present (about what the lighted up control bulb will testify or voltmeter indications), it means, that the chain part between connection and the storage battery is serviceable. |
| 14. Continue check of other part of a chain in the same way. |
| 15. When the point where pressure is absent will be found, it means, that the malfunction source lays between this point and the previous point where pressure was present. The majority of problems is connected with bad connection. |
| 16. The negative plug of the storage battery is connected to "weight" of the car – to metal of the engine / of a transmission and a car body – and the majority of systems of the electric equipment are developed so that one feeding wire approached to an equipment element only, and the current came back through metal of a body of the car. It means, that fastening of an element of an electric equipment and a car body are a part of an electric chain. Therefore, the bad or oxidised fastening can be the reason of the big number of malfunctions in system of the electric equipment: from a full exit of a chain out of operation before its unreliable work. In particular, bulbs can burn dimly (especially if other chain using the same point of grounding) is included, engines (for example, engines of screen wipers or the radiator fan) can slowly work and inclusion of any chain can influence work of other chain. Notice, that on many cars connecting earthing strips between various units of the car are used, for example, between the engine / a transmission and a body, i.e. usually when between elements there is no metal contact because of use of rubber fastenings etc. |
| 17. For check of reliability of grounding disconnect the storage battery and connect one of щупов an ohmmeter to "weight" of the car. Connect the second щуп to a wire or a point of grounding which is necessary for checking up. The resistance registered by an ohmmeter, should be equaled to zero, otherwise, check up connection as follows. |
| 18. If you consider, that connection is not perfectly in order, disassemble connection and smooth out to pure metal a contact surface and the plug of a wire or a surface of an earthed element. Remove completely a dirt and corrosion traces, then by means of a knife remove a paint coat to receive reliable connection of metal with metal. At assemblage reliably fix connection; at installation of the plug of a wire use gear washers between the plug and |