C5 Electrical Problems

I've been having problems with my '98 CF. These are the syptoms. This
morning I tried to start the car and it would barely start. Later on in the
day it wouldn't start so I had to jump start it. While looking at the
battery meter I see the voltage varying as low as 10 volts to as high as 14.
It doesn't matter if I rev the engine, the volt guage seems to vary no
matter what. I can see the diplay occationally flicker. If I tun the blinker
on the speed of the blink occationally varies.

Is this a bad voltage regulator, a bad battery, or will I need a whole new
alternator? Can just the voltage regulator be changed or am I going to have
to replace the alternator? What could be wrong?

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Many thanks,

Steve