To start an internal combustion engine, a small electric motor, a starter, is needed. In order for the engine to be started at all, the starter must spin it up to a speed of at least 300 rpm. This is only possible if the starter works flawlessly and the battery has sufficient charge.
The starter consists of a drive housing, a relay armature housing and a manifold housing. An armature and a collector, as well as a brush holder, are placed in the armature housing and in the collector housing. The brush holder contains carbon brushes, which, although slowly, but still gradually wear out. With a strong wear of the carbon brushes, the starter cannot work flawlessly.
A gear drive is located in the drive housing. If voltage is supplied to the starter through the ignition switch, the traction relay located in the starter housing pushes the gear along the screw slots to the flywheel ring gear. As soon as the gear reaches the stop to the spindle, there is a mechanical connection with the flywheel. The starter motor can now bring the engine up to the required RPM. If the engine starts, the gear is accelerated by the engine. For some time, it rotates faster than the starter and disengages, which leads to the termination of the connection between the starter and the engine.
Since a large current is required to start an internal combustion engine, the condition of the power wires should be checked during vehicle maintenance.