If the starter does not rotate, you should first check for a voltage of at least 8 V on terminal 50 of the traction relay. If the voltage is below this value, you should check the wires related to the starter circuit according to the electrical diagram. Whether the starter engages at full battery voltage can be checked as follows:
Set the box to neutral, turn on the ignition.
With an auxiliary wire with a cross section of at least 4 mm2 bridge terminals 30 and 50 of the starter, see also section "Start Relay Test".
If at the same time the starter works normally, then the reason lies in the wiring. If the starter does not work, it should be removed and checked.
Test condition: Wire connections must be well secured and not oxidized.