Hi, Posted this in a similar thread too.

Output should be between 14.1 and 14.9 volts at 5000rpm, measured across the battery terminals.

Personally I would double check the regulator installation and very closely inspect the connections at the connector block, also make sure the connector is pushed fully home.

If you are sure the new regulator has been properly installed and the contacts in the plug to it aren't damaged it may be worth checking that the connector from the alternator stator windings is sound, it's located behind the rear master cylinder on the Z, enclosed by a rubber boot - it's the 3pin connector with white wires. You could also measure the resistance of the windings (you need an ohm meter), the readings between any pair of windings on the alternator side of the connector should be between 0.224 and 0.336 ohms. Check also the resistance readings between each winding and the chassis/earth, they should be infinite, i.e. no reading. If there is a reading it could indicate a short in one of the stator windings.
Stator windings very rarely give any problems though (in any vehicle), usually it is a wiring fault in a loom or water ingress at a connector that causes problems here.

I hope you find the problem quickly.

Cheers.

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