i have a sync. motor 8/10 RPM to check the current i conn. muy digital multimeter ACA range in series., but i didn't get nothing. i conn. it directly to AC and it works, i used differnt ranges, still nothing.
i noticed motor's shaft doesn't turn when i conn. it to measure I why ?
My meter is very old. Do u think ACA is not working ? or out of cal. ?

 

It may be that your meter's fuse is blown. Most have an internal fuse to protect them from excessive current, like when being used to measure voltage while set on a current scale.

 

Did you connect the red probe into the amperes plug?

I think you left it in the Volts/Ohms plug.