i think its bad im taking it in and geting it replace but if i unpluge the s termail it charges at 12 volt no mater how much i rev it but im with my self to eather run it with a s termail pluged in for get a new vr

 

S terminal unplugged you're likely just reading battery voltage and not charging at all.

 

i tested it at the alt

 

The battery terminal at the alt will read battery voltage with the truck running or not running.

 

when the truck is off it read 10 volts

 

Joe, 12 volts will not charge the battery.

Electricity(Current) flows from a higher voltage to a lower voltage. The battery is right around 12V. So, in order to charge the battery, the voltage in the battery cables has to be > 12V, usually 13V-14V.

So leaving the S unplugged will not solve your problem.

Unplugging the S, if i'm not mistaken, disables the alternator.

Try a new voltage regulator.