Odometer--Help!

The odometer and tripometer (sp?) on my 1996 V6 Mustang have both stopped working. All the other instruments are working fine, and I have not made any modifications to anything since I bought the car (used).

I called my mechanic, and he said it was a serious problem, and I would have to take it to a specific state-licensed (Florida) mechanic to be fixed (he is not licensed to fix this problem).

Having searched a number of forums, best I can tell is that the problem is one of three things: a fuse, the teeth in a gear-like component, or wires.

Can anyone tell me how (or whether) I can determine which of these it might be? Even if it is not something I can fix myself (which I assume it is not?), I'm nervous about bringing it to a mechanic without having some good idea of the problem!

Many thanks for any help/information anyone can provide!!

I actually found someone to fix it It was a gear thingy (no idea of the name) behind the instrument panel. The rubber cogs had simply worn out. Apparently, this happens to a lot of 96 Mustangs! The guy fixed it for me for $100, but told me that had I brought it to a Ford dealer, they would have both reported it to the state (so the registration would have forever more said "estimated" mileage) *and* charged me over $400!