Probably the points are stuck together, or else the ground you're
connecting it to is not as good as it needs to be... the PO's mechanic
screwed the regulator to the back of the dash, causing high readings on
the temp and fuel gauges :-) . After fixing the ground, though, the
regulator worked properly for about half an hour, then intermittently
for another hour, and then I ripped it out and built a solid state one,
much like what Ed is selling today. No problems with the solid state one
in the last six years.