Anyone know what the common reasons are why so many C3's seem to have non-working clocks?

...well I found out that the metal contact points "burn up" and that's what shorts out the clocks. My guess is that going 120 mph causes the clock to shake a little and this wears down the contact points to its eventual doom.... Wilcoxcorvette.com has quartz "do it yourself" replacement clock kits for $60....just under half the price of a new one.