Do I need a new alternator?

[yellowdog5]

I looked at a couple different youtube videos on how to check my alternator with my multimeter. It appears that the ground is good, the hot connection is good, but it's not charging the battery. I think this means the alternator is not working, am I correct? 79 k2 400.

 

[75gmck25]

Stock wiring scheme runs the charge wire from the terminal on the starter up to the Bat connection (screw terminal) on the alternator. You also need to have the two wire plug connected to the alternator. One wire in the plug is also 12 volts constant (this is the voltage sense wire) and the other terminal is 12 volts switched from the ignition switch. Did your check all these connections?

How are you checking it and what readings are you getting?

 

[yellowdog5]

I left everything connected, black on neg. terminal and red on alternator case reading was .05 , red on pos. post and black on the alternator post with the nut holding the wire to it, reading was .1 both were at 1500 rpm. Not positive those were the exact readings I didn't write them down but they were below the .1 and .3 that the video said were necessary. When I tested the alternator on the battery terminals the volts didn't change from 12.5 when I started the engine.