BMW 7_aya the E38 series from 1994 to 2002
1. Introduction
2. Governing bodies and methods of operation
3. Settings and routine maintenance of the car
4. Engine
5. Cooling systems 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. Cardan 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 fixtures
14.3. Screen wipers and washers
14.4. Other electric equipment
15. Schemes of electric equipment


14.1.4. Relay

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, fog lights and other) relays are used. 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 installed in the assembly block under the dashboard and in blocks in a motive compartment (see Specifications in the Head Onboard electric equipment). The description of check of serviceability of functioning of the relay is given 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 (Schemes of electric equipment), it is necessary to remember that approach to check of any relay in principle is identical in all cases.

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

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.


  1. Before removal of the relay make sure that the corresponding contour is cut off power.
  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 ground the second plug of management, – the relay has to publish click. 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.
  3. At the connected wires crossing points check existence of conductivity between the contour V/V plugs.
  4. At negative result of check replace the relay.

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14.1.3. Safety locks
following page"
14.2. Lighting fixtures