Checking the charging system

How do I check the charging system on my 1976 Kawasaki kz400-D. I accidentally reversed the leads from a jump box and fried a few wires but when I hook up the bike with jumper cables to a car, with a battery in it, it will run just fine. I want to know how to check the R/R with a meter and know the ohms etc and how to properly check the system. TIA

Just fried a few wires????  ......That was all???...basically, at idle it should be a little about 13 VDC, and if reved, it should go above 14 VDC.    It is really a 14 VDC system.

I bet the factory service manual has a pretty good testing procedure.

www.kzrider.com/filebase-alias?task=down...id=1231&catid=11&m=0

Older vehicles with few electronics tend to brush off a bit of "reverse polarity" action fairly well. More modern ones would need new control units for just about everything

Yeah just a few. It burned the wire coating but it stills runs very well. I just don’t think it’s charging. 

As suggested there are tests in the service manual that I would suggest you read and run. You may find info in this post of interest as well.
kzrider.com/forum/2-engine/621566-650-75...compatability#911518