picked up a dmi lower mount with a nd alternater wondering how to wire with the three wire round plug along with the main lug ,is one terminal for switched power and others for warning light ?any help many thanks.

Andy has a diagram here

http://www.arengineering.com/alternatorbracket/ND_bracket/frame1.htm


you say one wire but you mention a standard plug?

you have the heavy alternator output lug than the three terminals. one is key on (ignition), one is for the charge lamp and the third is for a remote voltage sense. with this line you can wire the system so the alternator uses the voltage at a remote point for it's output reference