Voltage regulator overcharging

Do you have a good engine to frame ground
You could use a piece of wire with say a 10 amp fuse connect it directly between battery positive & Alternator blue terminal the charging voltage should drop to normal voltage if it does not then either the regulator has a bad ground connect try a piece of wire directly from the regulator frame to the negative battery terminal if the voltage is still high it could be a bad regulator
Also when you have the blue wire from the positive to the regulator you will not be able to turn the engine off at the key as it will also feed the coil circuit.