Speedometer Problems

[vmurh]

One of three Mustangs i have is a 97 V6 5 speed. At 80,000 miles the speedometer start going crazy. When you would start to move at a normal pace the speedo would race up to 80mph. Various times the thing would register incorrect speeds mostly showing faster than actual. I spent $300 on a new speedo head to fix the problem at a Ford Dealer.

This work for about 15000 miles, now i have the same problem again.

What could be happening? I got to belive someting is causing the speedo problems other that just changing out the speedo head.

Anybody with a similair problem?

 

[PhantomGT]

Seems to me to be your speed sensor which is located on your rear axle, maybe the wires have a short or aren’t connecting properly, it's not really worth fixing but if you really wanted to, I’m sure your shop could tell you how to do it yourself to save the $$$$