Checking the relay (BMW 5 Series E34)

The easiest way to check a relay is to replace it with a known good relay. As a rule, relays are checked this way at a service station. However, since there is not always a stock of all types of relays at home, the following technology for checking the so-called working relays is recommended, which, among other things, are used to turn on fog lights and main lights.

Remove the relay from the socket.

First, use a voltage tester to make sure there is voltage at terminal 30 of the relay block. To do this, connect the tester to ground and insert the other end into the terminal 30 socket. If the tester's LED lights up, voltage is present. If there is no voltage, find the open circuit from the positive pole of the battery to terminal 30 using the electrical diagram.

Make a jumper from a piece of wire, stripping its ends.

Connect this jumper between terminal 30 ((+) of the battery, voltage is present constantly) and terminal 87 of the relay block. The location of the relay contacts is indicated on the relay and on the relay block.

If, for example, the high beam headlights light up when the jumper is inserted, then the corresponding relay is defective.

If the high beam headlights do not light, use the electrical diagram to find and repair the open circuit from terminal 87 to the main headlights.

If necessary, install a new relay.