Testing Methods

Hi, I'm not sure if this is the right forum but I was wondering if anyone could tell me how to test the field coils and armature in an angle grinder;
engine starter; drill motor... I'm new at this so any help would be awsome.
Thanks , Danny

Basically these are whats called Universal Motors. If the Commutator rings are OK, than you can measure the DC Resistance of each coil by putting an Ohm meter on Opposite sides of that ring, checking one set of coils, than move each probe one pad to the right, to test the next coil. Continue till you have gone half way around. All Coils should measure Exactially the same Resistance.

A better test would be performed the same, but Measuring Inductance of each coil, also "Q" or a Ring Test. This would better determine a Shorted turn.

Even Better, Get a "Growler", Specifically made for testing Armatures.

Hope this helps...........Gary

Thank you I'll give it a try. Where can one find this "growler"?

It is called a "growler" from the vibration sound it makes when a short is detected from what I can remember. Search for growler tester on Google