Alternators

Alternators have a lot of parts in them and are one of the main parts is is the rotor, the rotor is the electromagnet takes power from the starter and the resistor controls where the power goes. Another part of the alternator is the brushes, the have to be at least 4mm long and on the alternator that we tested in practical they were 7mm long so they still had plenty of life in them. You can also box test the alternator for short circuits, if the short circuit light comes on then there is a short circuit in the alternator, if the light comes on but is very dim then it means the circuit is fine. In a rotor winding ground test it should show infinite on the ohms setting of the millimetre to be in good condition. The main job of the alternator it to keep the battery charged so that when you accessories are on the car doesn’t go flat. If your alternator blelt snaps then your car will still run but your battery will evently go flat, this can also happen if you belt is old it can get worn down and start slipping. The alternator is very important part of the car and is always good to make sure it is in good shape

 

Above I have attached a picture of a common alternator attached to an engine with arrows pointing the direcdtion of the alternator belt and some of the exterior parts

This is a labeled diagram on the parts inside and out of a common alternator