16.2. The general information on search of malfunctions in electric chains
The typical electric chain consists of an electric component, switches, the relay, motors, safety locks, fusible inserts or the breakers of a chain connected to this component, and also conducting and sockets which connect a component with the battery and the chassis. To help you to reveal malfunction in an electric chain, at the end of this Management there are Schematic electric circuits.
Before undertaking any faulty electric chain, at first study its assembly diagram completely to understand, of what it consists. For example, sometimes it is possible to narrow essentially troubleshooting area, having checked work of other components connected with this chain. If some components or chains, that failed at once, it is possible that a problem in safety locks or in grounding since often some chains pass through one connection of safety locks and grounding wires.
Malfunctions in electric chains usually occur from the simple reasons, such as easing or oxidation of the contacts, the burned-down safety lock, the melted fusible insert or malfunction of the relay. Therefore before to begin search of damages, visually check a condition of all safety locks, wires and contacts in a faulty chain.
The main devices necessary for detection of malfunction in an electric chain, include a tester, the digital voltmeter with high resistance, a tester of conductivity of a chain and a wire from a set for car start from an external source with the built-in breaker of a chain which is used for round of components of a chain. Before trying to reveal malfunction by means of testing devices, glance in assembly diagram to define, in what place them to connect.
Tension check in a chain
Check of tension is carried out when the chain badly functions. Connect one end of a tester of a chain to a negative wire of the battery or to reliable grounding.
Connect other end to one of sockets of a tested chain, it is preferable to what is closest to the battery or to a safety lock. If the bulb of a tester burns, means, in a chain there is a tension that, in turn, means that on a chain site between the socket and the battery of malfunction is not present. Continue to check the remained sites of a chain in the same way.
When you will reach a site in which there is no tension, will find a malfunction place. More often the problem appears in bad contact.
Remember that in some chains tension arises, only when ignition is included.
Finding of malfunction in a chain - quite simple business if you remember that any electric chain is the electricity going from the battery on wires through switches, the relay, safety locks and fusible inserts to various components of an electric chain (to bulbs, motors etc.) and to the earth from which it passes back to the battery. And any malfunction in a chain is a violation of a stream of an electricity from the battery or to the battery.
Search of a place of short circuit
One of methods of search of a place of short circuit in a chain is to disconnect a safety lock and to connect on its place a test bulb or the voltmeter. In a chain there should not be a tension. Move electroconducting here and there, watching a test bulb. If the bulb joins, means, on this site there is a short circuit on the earth, possibly, isolation somewhere was wiped. As each component of a chain is checked, up to the switch.
Carry out the test for grounding to check, whether the chain component is correctly earthed. Disconnect the battery and connect one end of a tester of conductivity of a chain to reliable grounding. Connect other end to a wire or the socket of checked grounding. If the bulb lights up, grounding is made correctly. If does not light up, it is wrong. In this case disconnect the socket and carefully clean all connecting details. Again connecting the socket, use whenever possible jagged washers and reliably tighten all bolts and other fixture.
Check of conductivity of a chain
Check of conductivity of a chain is made to define, whether is not present in a chain of breaks - whether well she carries out a current. For check the conductivity tester is used, the current in a chain is switched off. Attach connecting wires by both ends of a chain and if the test bulb is lit, means, the chain carries out a current well. If the bulb is not lit, somewhere in a chain there is a break. The same procedure is used for switch check, only the tester of conductivity is connected to switch plugs. At the switched-on switch the bulb should light up.
Disconnection search in a chain
At visual definition of a place of possible disconnection of a chain often there are difficulties since oxidation or shift of contacts is latent by sockets. Disconnection in a chain is often caused by oxidation or weakening of contacts. Having simply stirred socket contact on a perceiving element or in conducting, it is possible to restore the opened chain, at least temporarily. Disconnect the socket and spray it water from an aerosol ballonchik. On simple sockets sometimes it is possible to bend carefully socket contacts inside to improve contact - however be not fond of it not to damage the socket.