Examination
1. If it is not possible to find out how the relay is connected to the corresponding electrical circuit according to the wiring diagrams (see Wiring diagrams - general information), it should be remembered that the approach to checking any relay is basically the same in all cases (see below).
2. In most relays, a control loop is always connected to two of the contact terminals. When voltage is applied to these LV terminals, the current begins to circulate through the relay control winding, as a result of which the large contacts of the working circuit of the consumer of electricity are closed. The rest of the terminals are the terminals of the working (BB) contour.
3. In order to facilitate the identification of the relay terminals, an explanatory marking is usually applied to its body with an image of the key connection diagram.
4. Connect a fused jumper wire between one of the relay control terminals and the positive battery terminal. Using the second jumper wire, ground the second control terminal - the relay should make a click. Some of the relays require the polarity of the connection - if there is no click, try reversing the polarity of the control terminals. With jumper wires connected, check for continuity between the terminals of the BB circuit by connecting an ohmmeter in accordance with the key diagram on the relay housing (see accompanying illustration).
5. If the test fails, replace the relay.