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Relay - the general information and check of serviceability of functioning

general information

The principles of operation of various types of relays

For a power supply or control signal to many of the power consumers in the car (such as the components of the fuel injection system, a horn, a starter, the fan (s) cooling system, fog lamps, etc.) Used by the relay. Actually, the relay is an electrical switch that provides circuit BB circuit for signal NV. In the event of a relay failure fails the appropriate functioning of the consumer. Most of the relay is placed in the engine compartment, the other "scattered" on the car. Description check serviceability of functioning of the relay is shown below. Faulty relay must be replaced.

Check

Correct connection relays can always be determined on to Part H of this Chapter wiring diagram.

Typically, two of the terminals are always connected relay control circuit. When applied to these terminals HB voltage current starts to circulate through the coil control relay, resulting in the closure of a large working contacts contour consumer. The other terminals are operating terminals (BB) circuit and are closed to each other when power to the control loop.

In order to facilitate the identification of the relay terminals on the casing is usually applied explanatory labeling schemes connected with the image of keys. If such labeling is not, refer to the connection diagrams (see. Wiring diagrams).

To check, connect an ohmmeter between the terminals BB circuit relay - relay normally open type conductivity should be absent. Now equipped with a fuse plug the jumper wire between one of the control terminals of the relay and the positive battery terminal (B +). With another jumper wire to ground the second terminal management, - the relay is to publish a click, followed by an ohmmeter fix the presence of conductivity (relay normally open type). Some relays require that we comply polarity.

At negative result of check replace the relay.