I will be replacing my dynamo to an alternator i want to test my 2nd hand alternator on the bench can someone please list a quick talk through please -
A bit late I know, but alternators are hard to bench test. We've got a friendly alternator man that will test for free.
They certainly can be tested on the bench using a drill via a socket to match the pulley nut. Electrically connect the Alternator B+ to Battery + Alternator earth to Battery - Alternator D+ or 61 to Battery + via a 12 v 2 or 3 watt bulb. This is good enough to confirm it works make sure the bulb goes off when drills running.
It should work as it the same circuit as on the van its a basic test to full test you could put a load on it by connecting some headlight bulb to the battery
The heaviest load should be the initial peak current needed to charge a completely flat battery. If you can fit an ammeter into the circuit, it'll confirm not only that the alternator works, but works fully
Take it down to your local Bosch dealer, or test it in the van. You won't have much luck on the bench.