I remember a while back (maybe pre crash), that there was a post that outlines the a method to check an alternator is operational while off the engine. Can anyone remember it or know the method? I think it might have been as simple as connecting it to a battery (for a short period) and if it turns then it is working. I.e. if it turns when electricity goes in then electricity will come out when it turns.
Don't try that method with an Alternator ...bridging the field and applying voltage to see if it runs as a motor only works on a Dynamo.
I made a wiring harness to test alternators a while ago. Its only a few wires and a bulb. Don't think it would work with an alternator with an external regulator though. Croc clip goes to battery positive, ring terminal to the main alternator terminal and the spade goes to the warning light terminal. Earth alternator to battery. Light shold come on. Spin alternator with an electric drill on warp speed (spin it the right way) and the light should go out. Use multimeter on battery terminals and it should read close to 14V if its OK.
i've bench tested used modern alternators before i've fitted them if they were awkward to get to and fit by wiring up correctly to a battery ie test lamp as a charging light and wired the b+ connection to battery positive and jump lead from vise to battery negative, with a voltmeter between the battery terminals then i spun the alternator up with the correct sized socket on the end of a airgun when the charging light goes of the battery voltage starts going up till it get to 13.5-14.5 volts hope this helps obviously if you have a external reg alternator you need to wire the reg in or you will damage things
