Checking the power supply and glow plug relay (BMW 3 Series E36)

Before disconnecting the battery, conduct a survey of the fault memory at the service station, since the stored failures are trying.

Disconnect the ground wire from the battery.



Remove the control unit cover. The control unit is located in the right rear part of the engine compartment on the bulkhead under the windshield.



Press the locking hooks on the left and right and remove the relay.



Check the strip fuse next to the connector and, if it is defective, replace it. Before doing this, identify and eliminate the cause of the overload.



Unscrew the thick positive wire from the top side of the relay housing.

The figure shows the diagram of the preheating relay. The location of the connection contacts is shown on the cover of the preheating relay.



Connect the battery and connect the voltage tester to terminal 15 and ground. Turn on the ignition. The tester's LED should light up, otherwise check the electrical connection to the ignition switch.



If the LED lights up, check for breaks in the wires to the glow plugs and replace them if necessary. Otherwise, replace the preheat relay.

Install the control unit covers and engine linings.