The invention relates mainly to a starter for a heat engine of a motor vehicle comprising: at least one electromagnetic switch comprising a positive output terminal, at least one electric motor, said electric motor comprising: a stator comprising coils, each of the coils being wound around a pole piece to form a pole, at least one brush cage (43), at least one positive brush (35) mounted in said brush cage, an electrical path between said positive brush (35) and the positive output terminal (32), and at least one thermal protection (96) located in said electrical path, in which said thermal protection is able to disconnect said two elements (93, 95) when the thermal protection has a temperature above a temperature threshold for electrically disconnecting said positive output terminal with respect to said positive brush (35).