I checked some other previous postings, but couldn't figure out yet.
Sable 93. The Speedometer was intermittently working, but in the past few months it completely stopped. (Now it always shows zero mph. When it worked, it was correct). The speedometer is analog, needle type. Together with speedometer, cruise control stopped working too.
I guess I located the cable coming from the firewall. That cable goes thru a round metal block (see picture, I guess it is called the "gear":)