1996 V6 Mustang Tachometer and Odometer Problems (Trying to Diagnose)

Hey there! I'm a proud new owner of a 5-speed Manual Transmission 1996 Mustang! It's my first car, and its been great with it so far, although it needs its fixes. Right now I am working on the tachometer and odometer. The former was working well until recently, the latter simply stopped working. Everything else on the gauge cluster works (although I have my suspicions on the thermometer).

The tachometer used to idle even though I accelerated until either I stopped accelerating or stepped on the clutch, at which the needle would launch up to a ridiculous measure, and eventually made a full spin over the limit and now is lying below the 0 mark stick.

The odometer just doesn't mark new miles, so I do not know if the problems are connected. Speedometer does work.

I'm trying to find any help on diagnosing the problem. I would like to know where do these gauges get their measurements from, and from where to where do the cables run in the car to see if they are working. Thanks!

EDIT: I used the search feature, but didn't find helpful threads for this specific problem... :\