My brother in law has turned to me for help on his 91 Dodge pickup. His speedometer works but his odometer does not. He told me that he had the entire speedometer and odometer changed. It did not fix the problem. I was at the wrecking yard and picked up a complete dash gauge setup and still no dice.The mechanics at the local dealership don't even remember one this old. I was told that the speedometer and odometer may run off of different sensors. Does this sound right? One guy told me the speedo ran off of the rear end and the odometer ran off of the tranny. It has the drive coming out of the back of the tranny that converts to wires and feeds the dash gauges.