1998 dodge ram 2500, speedometer does not work

Most likely the rear axle speed sensor or its wiring

Sounds like your speed sensor on the rear end. Could just be a loose connection check the harness is securely pluged into to sensor. I know on my 02 ram I have abs sensors that go in to my hub bearings, if you have this that could also be your problem. when i installed my new hubs I bent the tab on the connector to far and my light came on and off during driving. I had to tap down my connector.

there is an ABS sensor on top of the rear axle, and they are known to cause these symptoms-check the wiring, connector, and replace it if necessary, they are about $30 and is held in place with one bolt.

Does the speedometer work? Out might have a bad speed sensor in the rear axle. Did you have it scanned for codes?

you have an code stored in the abs module.likely a bad rear wheel speed sensor.as it runs the speedometer.check wiring to the sensor.it is located on the top of the rear diff housing.hope this helps.

Have you had the abs scanned? It is likely the speed sensor in the rear differential. It is a common problem on these.

Change the speed sensor in the top of the rear differential

You must have ripped the wires off underneath your truck, and you probably don't have brake lights anymore either. Better get somebody to repair it as soon as you can.

Replace the speed sensor in the rear end.

No definately the speedo....