Starter fault diagnostics (BMW 5 Series E34)

If the starter does not turn the engine, first check for voltage at terminal 50 of the traction relay of at least 8 volts, sufficient for the traction relay to operate. If the voltage is lower than this value, check the starter current circuit wires according to the electrical diagram. Checking the traction relay operation when full battery voltage is applied is performed as follows.

Put the gearbox in neutral and turn on the ignition.

Then, using an auxiliary wire with a cross-section of at least 4 mm², short-circuit terminals 30 and 50 on the starter, see the electrical diagram.

If the starter works clearly, the fault is in the wires leading to the starter. If the starter does not work, it should be removed and checked.

Test conditions: Reliable wire connection and unoxidized contacts.