I just picked a up '91 Ser. The speedometer doesn't work. I was reading a bunch of threads on this topic. My problem is a little differant than other people *** so I decided to try and get a little help from you guys. My speedometer is stuck on 15mph. However odometer and trip odometer still work. Could this still be related to the cable? If not, what else can i try to fix this problem? Thanks in advance for any help.