Merc Cougar Odomoter/Cruise

I recently purchased a 1993 Mercury Cougar XR7 with the 3.8 v-6 and automatick transmission with overdrive. The car has 142000? Miles. The speedo is analog.

The odometer and crusie don't work. The speedometer does work. I was told that the speed sensor in the transmission was the problem by one person. I was also told by someone else that there is a gear in the speedo that makes the odometer work and effects the cruise as well.

Which of these are right or are they both right? If so, where do I start to diagnose/fix the problem?

Thanks for your time and answer in advance.