Brian,
It isn't worth your time to mess around with the clock. You can get it refurbished with a one year warranty for $40. If that part has to be replaced, I think that may be an additional $15. The place I recommend is:
http://www.clockwks.com
You hear a lot of criticism about old car clocks. The majority of problems occur when the cars battery weakens and it burns out the points in the electric winding mechanism. I have an old fashioned clock in one of my '57s that has been going great since '91.
Tom
P.S. If you want to check your clock to see if it works, ground the case and apply power to the FUSED power wire.