Hi there.
You don't calibrate it you just set it. Use a GOOD voltmeter. (lol)
-Put the steer tire in the straight ahead position.
-turn key off
-loosen coupling
-Connect (back probe) your positive lead to wire 68 (terminal 2, middle connection) on the 3 pin potentiometer connection.
-Connect your negative lead to battery negative
-turn key on
-set voltage to 2.5v +/-.02v (between 2.48 and 2.52 volts)
-tighten coupling and recheck voltage.
Don't turn the wheel while you're setting the voltage.
The dash display method is the same thing but it just reads the voltage on the dash.
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