HELP! datsun 521 over charging

[sergio521]

So today the Datsun 521 started to charge 16 volts to the battery I chacked the alternator it good changed the voltage regulator it rand fine until I trunes it off and back on boom it started charging 16 volts agin am tuning and amp idk if it can affect it but it switch to turn on when the key is turned on its grounded to one off the seat belt bolts and it gets it power from the battery

[DanielC]

It is normal for a Nissan voltage regulator to run a higher voltage when the engine is first started.  The battery is benefited by a higher initial voltage, because it was just discharged by cranking the engine.   There is a chart in the 1973 L-16, L-18 service Nissan service manual

Down load it from this page, about 3/4 of the way down.

http://www.davidcmurphy.com/olddat/620tech.htm

 

Do you know your volt meter is good?  What volt meter are you using?

 

It is also possible the voltage regulator is bad.  It is more possible there is a bad connection, or a missing wire.  Is there a ground wire from the negative battery cable connection at the cylinder head to the alternator frame?  From the alternator frame to one of the bolts holding the voltage regulator to the inner fender? 

is the alternator and regulator stock, or have you or somebody changed things?

[banzai510(hainz)]

I notice if one buys the Echlin brand USA mechanical ones from NAPA that they can over charge.

 

I went with the Wells/airtex solid state brand.

[sergio521]

The alternator doesn't seem stock it has a Mitsubishi logo and voltage regulator I changed to one u can buy at AutoZone the ground cable to the head is there but not one to the frame of the alternator just the ground cable you screw in the voltage regulator has the ground also