96 Impala SS Odometer Fades out on and off

Considering buying a used 96 Impala SS and the
only real problem I found with the car was the
Odometer fades to black then pops back on with a
life of it's own....

I did find a fix kit online for it I guess it's a
common problem with those SS's yet I wondered when
that odometer goes to black does it STOP recording
the mileage?

If so then the actual mileage might be higher, or
is that just some sort of light issue (keeps
recording miles even when we can't view it).

I test drove the car for a bit but during that
time the light seemed to stay on fine for me (so I
couldn't tell if it was saving miles) the seller
said it comes and goes like that, yet he was
pretty sure it did still keep mileage when off
(but that he didn't pay alot of attention to it).

This is my only hesitation on buying this car,
seems to look and run very well, just was hoping
for a bit of input on that from some out here who
may know

How much should I expect to pay to have this fixed
from a dealer (or i might buy the fix kit online
and do it) - I can solder btw

& most important, when an odometer light goes on
and off like this, does it STOP recording the
MILEAGE during the off times?

Thanks for all input,

Bill :)
BillAustin  at commmmcast dot net