how do I check ground wires out of alternator?

[Lee]

A bout a month ago, I had smoke coming out of the engine hatch grill on my '78 SC. The next day, the alternator quit charging. I had the alternator out and checked, brushes replaced. I tested the B+ wire coming from the starter...it gets over 13 volts from the battery to the alternator. I checked the plug going into the regulator...it's getting 26.5 volts AC. I've replaced the regulator.

Still, no charge from the alternator. A buddy of mine told me I should check the ground next. I assume he means the three ground wires that come out of the alternator.

My question: How do I check these. I'm still learning about electricals, and have never done anything with a ground, other than replace it.

If I have to replace one or all of the ground wires...is it a terrible PITA?

I appreciate your help.