Bench testing an alternator?

[Pine]

Would it be possible to bench test a Beetle alternator? I mean full setup - hooked up to a battery, pilot light etc.

Can an electric drill be used to spin it fast enough to determine if it is charging or not?

[retrovan]

Yes you can, you need to have a charge light in the wiring as it uses this to excite the field.

You also need the regulator in place.

Please note that as she starts charging, you may find the drill not powerful enough to pull a charging alternator.

Herman

[Pine]

Yes you can, you need to have a charge light in the wiring as it uses this to excite the field.

You also need the regulator in place.

Please note that as she starts charging, you may find the drill not powerful enough to pull a charging alternator.

Herman

Thanks Herman!

[Eugene]

Come on Pine....hook it up to your bicycle

[Pine]

So I got this old alternator that I bought a couple of years ago at a local scrap dealer for R 50. It came mangled in a squashed fan housing, so I assume it was from a Beetle that was rear-ended. I eventually had to cut the fan housing and fan away from it with my trusty old baby grinder, and gave it a good cleanup. Seemed visually fine, and ran true when spun by hand. It is one of those alternators that has to be connected to an external regulator.

I found a solid state external regulator in the week at an old spares shop in Knysna. I have never used one of these before, as I was used to the larger metal Bosch regulators used by the 411s and 412s I previously had. The terminals have no markings, but a quick Google searched revealed the correct information, for connecting it to the alternator.

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So I bolted the alternator to a piece of timber, and hooked it up to the regulator and battery, and a makeshift pilot light.

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Just as I took out the electric drill, to spin it using a 19mm socket - the power went off - load shedding! I tried to spin it with my rechargable battery drill, but with no success - the RPM of the battery drill was just not enough.

So two and a half hours later the power was on again, and I could spin the alternator with my electric drill - and it worked!

I could clearly feel when the alternator started charging, the pilot light went out, and the Voltmeter jumped to the correct reading. Phew! What a relief...

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So today I can proudly announce that it is indeed possible to bench test a Beetle alternator, using an electric drill! I have done it myself

[73type2]

I suppose that if you have a variable speed drill you could more accurately control the speed at which the alternator spins.