7.1.1. General information
Opel cars have electric equipment system with 12 V.Elektrooborudovaniye's working tension is executed according to the single-wire scheme – negative conclusions of sources and consumers of the electric power are connected to a body of the car which carries out function of the second wire. A food of all lighting devices and electric units is carried out from the battery of lead-acid type recharged from the generator of an alternating current.
The present section is devoted to the description of procedures of service and repair of some elements of system of onboard electric equipment. Besides, procedures of diagnostics of malfunctions of electric equipment of the general order are considered.
On Opel started to establish the Controller Area Network (CAN) device. It unites separate monitors in the general scheme (the tire of data) that offers the following advantages: fast data transmission from one device to another, economy of a place at the expense of application of small payments and details, reduction of number of sensors at the expense of their multifunctionality.
Principle of work of CAN
Instead of the separate conductor for each signal only two general wires that allows to receive at the same time information on a condition of the majority of devices and sensors are used, without using thus separate toggle-switches and switches.
The tire CAN, receiving important information (for example, about malfunction), fixes it in the memory.
At repair of electric equipment and a power supply system of the engine disconnect a wire from the plug «–» the storage battery.
At replacement of safety locks it is forbidden to apply screw-drivers and the metal tool as it can lead to short circuit in electric equipment chains.
It is forbidden to disconnect the switchboard of ignition and the storage battery on the working engine as it will lead to failure of a regulator of tension and elements of the electronic equipment of the car.
At check of chains of electric equipment it is forbidden to close on "mass" of a wire (to check serviceability of chains «on a spark») as it can lead to failure of elements of electric equipment.
It is forbidden even to connect quickly a conclusion «30» generators to "weight" (to check operation of the generator «on a spark») as it will lead to failure of diodes of the vypryamitelny block of the generator. To check the generator on the car it is possible only the voltmeter and the ampermeter. In order to avoid failure of diodes of the vypryamitelny block it is forbidden to check their megommetry or the control lamp fed by tension more than 12 in, and also to check such devices of a chain of electric equipment on the car without a detachment of wires from the generator. To check resistance of isolation of a winding of a stator of the generator the increased tension it is necessary on the generator which has been removed from the car, at the conclusions of a winding of a stator disconnected from the vypryamitelny block.
At carrying out electrowelding works on the car it is necessary to disconnect wires from plugs of the storage battery and the generator.
Do not concern elements of system of ignition and high-voltage wires on the working engine.
Do not lay a wire of a low and high voltage in one plait.
At additional charge of the storage battery on the car by means of the charger disconnect wires from battery plugs.
Supply voltage stock-taking
Stock-takings of supply voltage are made in case of violation of functioning of an electric chain. Connect one of wires of a tester of electric chains or to a negative pole of the storage battery, or to well earthed point of a body of the car. Other wire of a tester connect to the plug of the electric socket of the checked chain preferably closest to the storage battery or a safety lock. If the control lamp of a tester lights up, the supply voltage on this piece of a chain is present that confirms serviceability of a chain between this point of a chain and the storage battery. Continuing to operate similarly, investigate the chain rest. Detection of lack of supply voltage speaks about malfunction existence between this point of a chain and the last from checked earlier (where the supply voltage was present). In most cases, a cause of failure is weakening of electric sockets and violation of quality of contacts (oxidation).
Searches of a place of short circuit
One of methods of search of short circuit is extraction of a safety lock and connection instead of it of a lamp sampler or the voltmeter. Tension in a chain should be absent. Pull conducting, watching a lamp sampler. If the lamp starts to blink, somewhere in this plait of wires there is a short circuit on the weight, probably caused by wiping of isolation of wires. Similar check can be made for each of components of an electric chain by turning on of the corresponding switches.
Check of serviceability of grounding
This check is made for the purpose of determination of reliability of grounding of an element of a chain. Disconnect the storage battery and connect one of wires of a lamp sampler having the independent power supply to the obviously well earthed point. Other wire of a lamp connect to a checked plait of conducting or the plug of the electric socket. If the lamp lights up, grounding as it should be (and on the contrary).
Checks on absence of break
Check is made for the purpose of identification of breaks of an electric chain After shutdown of a food of a contour check it by means of a lamp sampler equipped with the independent power supply. Connect sampler wires by both ends of a chain if the control lamp lights up, break in a chain is absent. If the lamp does not light up, it testifies to existence in a break chain. Similarly it is possible check also serviceability of the switch, having connected a sampler to its plugs. At transfer of the switch to the situation "Vkl" the lamp of a sampler should light up.
Localization of a place of break
At diagnostics of the suspect on existence of break of a site of an electric chain visually to find a cause of defect it appears quite difficult as survey of plugs on existence of corrosion or violation of quality of their contacts is complicated, in a type of limitation of access to them (usually plugs are closed by the case of the electric socket). Sharp twitchings of the case of the socket on the sensor or a plait of its wires in many cases leads to contact restoration. Do not forget about it in attempts of localization of a cause of failure of the suspect on existence of break of a chain. Unstably arising refusals can have the reason oxidation of plugs or violation of quality of contacts.
Diagnostics of malfunctions of electric chains does not represent a stubborn task under condition of a clear idea of that the electric current arrives to all consumers (a lamp, the electromotor, etc.) from the storage battery on wires via switches, the relay, safety locks, fusible inserts, and then comes back to the battery through mass of a body of the car. Any problems connected with refusal of electric equipment can have the reason only interruptions of supply on them an electric current from the battery or its return to it.
Wires, safety locks and relay
Protection of electric chains of the car against short circuit is provided with use of set of safety locks, breakers of chains and fusible inserts. The burned-down safety lock is easy for distinguishing from serviceable by survey of its transparent plastic case. Attentively examine a safety lock for identification of its peregoraniye. If the safety lock outwardly looks normally, but suspicions on its malfunction remained, make conductivity check between the knife plugs acting from its case.
At replacement of safety locks watch compliance of face value of a new safety lock to face value of the old. The safety locks calculated on a various current can look outwardly equally therefore it is necessary to give special attention to marking. Replacement of the burned-down safety lock on calculated on smaller – and especially big – a current is undesirable. Each electric chain needs different extent of protection. Watch that marking on the case of a safety lock corresponded to a current on which the corresponding chain is calculated. If the replaced safety lock immediately fuses, it will be not reasonable to continue its replacement. First of all, it is necessary to reveal and eliminate the reason of its peregoraniye. In most cases that appears short circuit in the electric chain, caused by break or damage of isolation of a wire.
Protection of some electric chains is carried out by inclusion in them fusible inserts. Inserts are usually used for protection of the chains which have not been equipped with safety locks, such as a chain of system of ignition.
Fusible inserts are similar to safety locks in the sense that their exit out of operation (oplavleniye) easily is defined visually.
For replacement of a fusible insert disconnect a negative wire from the storage battery. Take burned-down insert and establish on its place the new. Before insert replacement surely try to define the reason of the overload which has caused an exit of an insert out of operation.
Chain breakers (thermal relays)
Thermal relays serve for protection of such components, as electric drives of window regulators, locks of doors and adjustment of provision of headlights (electroproof-readers). Some of breakers of chains are established in the assembly block. Return of thermal relays to an initial condition on some models is carried out automatically, i.e. at overload emergence in a chain the thermal relay is instantly disconnected, then, after cooling, reverts to the original state. If contour return into position does not occur, it is necessary to make its check immediately. Normal functioning of the thermal relay confirms serviceability of a contour. Some of breakers are equipped with buttons for manual compulsory return to an initial condition.
Replacement of safety locks
For prevention of short circuit and overloads of consumers of electric energy separate contours are protected by safety locks. On Opel cars the safety locks corresponding to the last technical achievements are used, these safety locks have knife contacts.
Before safety lock replacement at first surely disconnect the corresponding consumer.
Hook a cover of the block of safety locks a narrow screw-driver and remove it.
Fused a safety lock it is distinguished on the melted metal strip. The arrangement of safety locks is shown on inside of a cover of the block of safety locks.
Take out a faulty safety lock the plastic tweezers being in a cover of the block of safety locks.
Insert a new safety lock of the same face value (current).
If again inserted safety lock fuses through short time, follows check the corresponding electric chain.
At all do not replace a safety lock with a wire or similar supportive applications as because of it in electric system of the car there can be serious damages.
It is recommended to have always in the car a set of spare safety locks of different face value. For their storage in the block of safety locks the corresponding place is provided.
Face value of a safety lock is put on a reverse side of the case of a safety lock. Besides, the case has the corresponding color by which it is possible to determine a nominal current.
For giving of an electric current to some elements of electric equipment of the car relays are used. Violation of serviceability of functioning of the relay leads to refusal of an element served by it. In case of suspicion emergence on malfunction any of the relay, it should be removed and subjected to check at service station or in a specialized repair truck. Replacement of the failed relay is made assembled.