Weekend workshop: save £200 in four hours
We explain how to test and rebuild your alternator for as little as £20
THE PC JOB CARD
ALTERNATOR REBUILD
Using a Lucas 15 ACR as a guinea pig, we'll reveal all you need to know to diagnose and rectify faults in a typical alternator. There are many designs, but the basics are the same.
You’ll need
Multimeter
0-75A ammeter
Relay and push switch
Charged car battery
Wire
Crocodile clips
Two- or three-legged puller
Soldering iron
Flux and solder
Will take (HR) 4
Will cost (£) 20
Money saved (£) 200
GET GOING
1 The basic principle
When a conductor (the wire) is moved through a magnetic field, a current flows in one direction. Reversing the wire’s direction reverses the flow. The output is increased by having a stronger magnet, using several wires or moving them faster.
2 The rotor
An alternator works by rotating a magnet – the rotor. Its magnetic field moves through static conductors. It comprises of a piece of wire wound around an iron core. The ends are connected to circular contacts, called slip-rings.
Want to read the rest of this technical guide? Choose a Print + Digital subscription. You'll get instant digital access PLUS FREE UK delivery so you'll never miss an issue again.