14.5. The relay - the general information and check of serviceability of functioning

The scheme of an arrangement of the relay on the car


General information

For giving of power supply or a signal of management on some of consumers of the electric power in the car (such as components of system of injection of fuel, a horn, a starter, the cooling system fan(s), fog lights and so forth) relays are used. Actually, the relay represents the electric key providing short circuit of VV of a contour on NV to a signal. In case of a relay exit out of operation there is a refusal of functioning of the corresponding consumer. The most part of the relay is placed in two assembly blocks located in a motive compartment, others are scattered on the car. The description of check of serviceability of functioning of the relay is given below. The failed relays are subject to replacement.



1. If it is not possible to find out a way of turning on of the relay in the corresponding electric contour according to schemes of electric connections, it is necessary to remember that approach to check of any relay in principle is identical in all cases (see further).
2. On the Maxima models considered in the present manual relays of four main types are used. One of them treat type normally closed, others - normally opened, at the third and fourth there are contours of the look which both is normally closed, and normally opened.

4. Usually the contour of management is always connected to two of contact plugs of the relay. When giving on these NV plugs of tension current begins to circulate on a winding of management of the relay therefore there is a short circuit of big contacts of a working contour of the consumer of the electric power. Other plugs are plugs of working (VV) of a contour.
5. For the purpose of simplification of identification of plugs of the relay explanatory marking with the image of the scheme of connection of keys is usually applied on its case. If similar marking is absent, it is necessary to address schemes of electric connections.

6. For check connect an ohmmeter between two VV plugs of a contour of the relay. In case of the relay of normally opened type conductivity has to be absent. Now connect the wire crossing point equipped with a safety lock between one of plugs of management of the relay and the positive plug of the battery. By means of other wire crossing point ground the second plug of management, - the relay has to publish click after which the ohmmeter will record conductivity existence (the relay of normally opened type). Some relays demand obligatory respect for polarity of connection, - if the click did not happen, try to change polarity of connection of plugs of management.

7. At negative result of check replace the relay.