BMW 7_ая the E38 series from 1994 to 2002
1. Introduction
2. Governing bodies and operation receptions
3. Settings and routine maintenance of the car
4. Engine
5. Systems of cooling of the engine, heating, ventilation and air conditioning
6. A power supply system and production of the fulfilled gases
7. Systems of electric equipment of the engine
8. Manual box of gear shifting and coupling
9. Automatic transmission
10. Kardanny and power shafts, reducer, differential and stupichny assemblies
11. Brake system
12. Suspension bracket and steering
13. Body
14. Onboard electric equipment
14.1. General information, diagnostics of malfunctions
14.1.1. General information
14.1.2. Diagnostics of malfunctions of onboard electric equipment
14.1.3. Safety locks
14.1.4. Relay
14.2. Lighting devices
14.3. Screen wipers and washers
14.4. Other electric equipment
15. Electric equipment schemes



14.1.4. Relay

For giving of power supply or a management signal 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 fan of system of cooling, fog lights and other) are used by the relay. Actually the relay represents the electric key providing short circuit In/in a contour on a low-voltage signal. In case of a relay exit out of operation there is a refusal of functioning of the corresponding consumer. Relays are established in the assembly block under the dashboard and in blocks in an impellent compartment (see. Specifications in Head Onboard electric equipment). The description of check of serviceability of functioning of the relay is provided below. The failed relays are subject to replacement.

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 (The electric equipment scheme), it is necessary to remember that the approach to check of any relay in principle is identical in all cases.

In most cases the management contour always is connected to two of contact plugs of the relay. When giving on these plugs of low-voltage tension the current starts 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 the worker (In/in) a contour.

For the purpose of simplification of identification of plugs of the relay explanatory marking is usually put on its case with the image of the scheme of connection of keys.


  1. Before removal of the relay make sure that the corresponding contour is disconnected.
  2. 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 the second wire crossing point earth the second plug of management, – the relay should publish click. Some relays demand obligatory observance of polarity of connection, – if click did not occur, try to change polarity of connection of plugs of management.
  3. At the connected wires crossing points check conductivity existence between contour In/to plugs.
  4. At negative result of check replace the relay.

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14.1.3. Safety locks
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14.2. Lighting devices