[Ross Nicol]

Malcolm
The current output from the Alternator varies depending on the load. A flat battery will require charging and the alternator will supply a high initial charging current and then reduce this current as the battery charges up. An alternator should have a high enough current output to run the engine and all accessories as well as provide the battery charging current.The younger generation with boom boxes have quite often found they have to fit higher output alternators as the sound systems add a significant load on the system.The alternator's output voltage is regulated to around 14.5v and a higher voltage indicates a regulator problem and a lower voltage indicates problems with the alternator output.I use a voltmeter in the GT40 to satisfy myself the alternator is working but don't rely on it's voltage reading to be accurate.Of course the voltmeter reads 12v without the motor running and if it climbs to 14v plus when I start up I'm confident all is ok.To check an alternator for maximum output would require placing a suitable load across its output eg bank up some headlights.

Ross