Odometer works.....Speedometer doesn't

[slangager]

I just had my Speedometer rebuilt by Palo Alto Speedometer about 500 miles ago on my 79 SC. Everything was great until this afternoon. The Speedometer is not moving anymore but the odometer is still working....Are these two parts associated? I always thought the odometer worked via the speedometer but that was just a guess.

Any suggestions before I start yanking parts?

Thanks in advance,

Stuart