Well if you can find a scan tool for the car, you can hook up to diagnostic terminal, go to live data and scanner should display speed (when driving). If it does, the gauge is bad, if not then sender OR wiring from sender to gauge.
I would go to junk yard and look for a 91 Dodge and get sender and entire IP, probably would be the cheapest route.
If you find one, get trim pieces, sensors, whatever you can afford.
Thursday, May 21st, 2009 AT 7:45 AM