No cable...electronic
Remove the heat shield on the firewall next to the turbo. (2) 10 mm
bolts. Now you can see the speedo sensor on the tail shaft of the tranny.
It has a pigtail plugged into it. I think it has (1) 10mm bolt holding it in.
Might have to remove the rear bobble strut to get to the bolt.
If the mph part is working but it doesn't record any miles, I would say speedo gear in the dash. This is a common problem. You can buy the little plastic gear for less than $30.00
Just search Mopar speedometer gear