Voltage regulator dart rallye cluster?

When it comes to wiring, You have to kinda throw the schedule out the window. This stuff can really suck up the hours. And if you lose patience, you often end up doing it twice. or more.
Yes you could make an external regulator, but you will still need to wire it to your gauge, and if the gauge is bad inside then you havent accomplished anything. Youre still gonna have to fix it.
You need to figure out which part is faulty; the reg. or the gauge. And to do that you have to isolate them from each other. And to do that it looks like you will need to get inside. Too bad your cluster isnt like mine, with the removable regulator.