How do you hook up a starter button in a 1980 Datsun 210?
I'm somewhat confused by your use of the term "starter button".
I assume you're referring to hooking up a remote starter allowing
you to spin the engine while you're working under the hood. First
make sure that the vehicle is in either park or neutral. Second,
make sure that the ignition switch is in the "off" position. Locate
the starter solenoid which is atop the starter assembly. Disconnect
the trigger wire at it's spade terminal. The wire will most likely
be yellow in color. Connect one end of your remote starter button
at this terminal on the starter and the other end to the positive