since 1993-1999 release
Repair and operation of the car
+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Repair of engines
+ 4. Heating system and ventilation
+ 5. Fuel, exhaust systems
- 6. System of start of the engine
6.1. Technical characteristics
6.2. Search of a source of malfunction in system of electric equipment
6.4. System of recharge of the accumulator
6.5. Connection of the auxiliary accumulator
6.6. Driving belt of the generator
6.8. System of start of the engine
6.10. Ignition lock
6.11. Switch of an alarm bulb of low pressure of oil
6.12. Oil level sensor
+ 7. System of ignition
+ 8. Coupling
+ 9. Transmissions
+ 10. Main transfer, half shafts
+ 11. Brake system
+ 12. Suspension bracket and steering
+ 13. Body
+ 14. Body electric equipment
The typical electric chain consists of an element of electric equipment, switches, the relay, engines, safety locks, the burned-through crossing points or automatic switches and wires and connections which connect all elements among themselves and connect them to the accumulator and mass of the car. To simplify troubleshooting process, at the end of this chapter electric circuits of system of electric equipment of the car are provided (see subsection 14.26).
Before check of a faulty chain study the schematic diagram of this chain to understand of what elements it consists. The source of malfunction can be found quicker if to define what of elements of this chain work normally. If several elements or chains fail at once, the problem probably consists in the fused safety lock or bad grounding as often one safety lock is responsible for several chains.
Problems with work of system of electric equipment are usually caused by the simple reasons, such as the oxidized or unreliable contacts, the fused safety lock, the fused burned-through crossing point or the faulty relay. Visually check a condition of all safety locks, wires and connections in a faulty chain before check of other elements of this chain. If you are going to use instrumentations, use schematic diagrams to define what connections need to be checked for failure detection.
The main devices necessary for search of malfunction in electric equipment chain, are:
– the device for verification of schemes or the voltmeter (or a bulb on 12 Volts with connecting wires);
– a control bulb with the power supply (or the device for check of integrity of chains);
– an ohmmeter (for measurement of resistance);
– probes with wires;
– a cap wire, it is desirable with the automatic switch or a safety lock which can be used for check of wires or elements of electric equipment.
Before search of malfunction with use of the control and measuring equipment study schematic diagrams to define connection points.
For search of unreliable connection or a point of short circuit (usually because of the bad or polluted connection or the damaged isolation) wires can be shaken by a hand to see whether the chain fails at the movement of a wire. In such way it is possible to find a point with unreliable connection or a point in which there is a short circuit. This method of check can be used along with other tests described in the following subsections.
Besides the problems connected with bad connection, the electric chain can have two other main malfunctions – existence of a gap in a chain or short circuit.
The gap in a chain can be caused by a rupture of any wire or lack of connection somewhere in a chain that will prevent a current of current. The gap in a chain will cause refusal of any element of electric equipment in work, but will not lead to burn-out of a safety lock of this chain.
The malfunctions connected with short circuit are caused by short circuit somewhere in a chain that leads to the fact that the current flowing on a chain begins to flow on other chain and, most often, leaves on weight. Short circuit is usually caused by a rupture of isolation that allows the feeding wire to concern either other wire, or the grounded element, such as a body. Short circuit leads to burn-out of a safety lock of the corresponding chain.
Before search of a source of malfunction or when carrying out repair in system of electric equipment do not forget that various types of wires have various color.
SEARCH OF THE RUPTURE OF THE CHAIN
SEARCH OF SHORT CIRCUIT
CHECK OF RELIABILITY OF GROUNDING
The negative plug of the accumulator is connected to the mass of the car – to metal of the engine / transmission and a body of the car – and the majority of systems of electric equipment are developed so that one feeding wire approached an element of electric equipment only, and current came back through car body metal. It means that fastening of an element of electric equipment and a body of the car are a part of an electric chain. Therefore, the bad or oxidized fastening can be the reason of a large number of malfunctions in system of electric equipment, from a full exit of a chain out of operation before its unreliable work. In particular, bulbs can dimly burn (especially if other chain using the same grounding is included), engines (for example, engines of screen wipers or the fan of cooling of a radiator) can slowly work and inclusion of any chain can influence work of other chain. Notice that on many cars the connecting grounding strips between various units of the car, for example, between the engine / transmission and a body are used, usually when between elements there is no metal contact because of use of rubber fastenings, etc.