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Testing an alternator and checking output

Check drive-belt tension by pushing or pulling the belt inwards at the centre of its longest straight run. Measure the deviation with a ruler. Read more

Renewing alternator brushes

Unlike dynamo brushes, alternator brushes normally last for several years. Electrical arcing between brushes and commutator, a major cause of dynamo wear, is far less common. Read more

How to test a car battery

When carrying out any tests on the engine while it is running or turning over, keep hair and loose clothing away from belts and pulleys. Read more

Update your charging system

Alternators are powerful enough to cope with the demand for current made by a modern car's electrics, but dynamos often are not. So if your car has a dynamo, and its output is inadequate, it makes sense to swap a dynamo for an alternator. Read more

The engine - how it drives its ancillary parts

The engine is, in many respects, self-sustaining: it supplies the power that drives a number of ancillary - subordinate - components without which it could not work. Read more

Fitting a new voltage regulator

When you have tested the charging system of a car fitted with an alternator, and the checks in How to test a car battery point to a fault in the voltage regulator, make sure that you need to replace it. The fault may be elsewhere. Read more