If the starter does not rotate the engine, first check for voltage at terminal 50 of the traction relay (minimum 8 V), enough for it to work. If the voltage is below this value, check the wiring diagram for the starter current loop. Checking the operation of the traction relay when the full voltage of the battery is applied is as follows.
Shift transmission to neutral, then ignition.
Then, with an auxiliary wire with a cross section of at least 4 mm2, bridge terminals 30 and 50 on the starter (see wiring diagram).
If at the same time the starter clearly works, the fault is in the wires suitable for the starter. If the starter does not work, it should be removed and checked.
Test conditions: reliable connection of wires and non-oxidized contacts.