you can go to speedometer and out of speedometer
The odometer has failed.
If your speedometer has stopped working just put the key in the off position and hold down the trip odometer button until you see some codes come on the odometer. That should reset your speedometer. I could not figure out which fuse was for the speedometer and some one told me about this and it worked right away.
check speedometer cable for possible disconnection; it comes out of firewall and goes to transmission
If you open the odometer, there are two small plastic gears. One is connected to the speedometer, the other to the odometer. The speedometer gear drives the odometer gear. In all likelihood, one of these gears is missing a few teeth. I have the same problem with my Ramcharger, same year.
it usually is the gear in the transmission Could be the vehicle speed sensor.
You can not legally.
I have a 2001 Dodge Stratus Coupe V6 and mine is a digital odometer located right under the speedometer.
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.
If the abs light is on, then you might have a rear axle speed sensor issue. If not, then you have a cluster problem.
Should read "...speedometer and odometer don't work..."
I would say you have a problem with the dash cluster. If both speedometer and odometer were not working I would say the problem may be the speed sensor but being only the odometer is out I would blame the cluster. I believe you will have to replace the cluster as a whole with a reconditioned unit. This will probably be a dealer item only.
i just changed the speed sensor on my 91 and it took care of that same problem.