Why doesn't odometer work in 91 Dodge truck yet speedometer works fine?

The issue with the odometer not working while the speedometer functions correctly in your 1991 Dodge truck is likely due to a problem with the odometer's internal gears or the odometer drive assembly. These components can wear out or become damaged over time, affecting the odometer's ability to record mileage. Additionally, a malfunctioning speed sensor or wiring issue may also contribute to this problem, though it's less common when the speedometer is still operational. Checking the odometer gears and connections may help identify the exact cause.