94 dodge 1500 4x4 5.9L. The problem is the speedometer only works sometimes. I have replaced the speed sensor on the transfer case. I also noticed that my abs and parking brake light was on so I changed the abs speed sensor on the rear differential. with all that I still cant get it to work. Need help please.

 

Does your truck go into overdrive? If the pcm didn't see a reading from the speed sensor it wouldn't go into od. It may be the gauge or wiring. The abs/brake lights both on means there is a fault in the abs somewhere. Disconnect the battery that should clear the abs code if it was the sensor on the rear.

 

Truck does go into overdrive

 

If it isn't bouncing in an out of O/D while the speedometer is screwing up, the problem is somewhere between the PCM, and cluster. (probably between the sensor, and the cluster, not sure which gets it first.)

 

Ok I'm gonna pull the cluster off tommorow and check wires. I hope I figure it out. It's really starting to **** me off

 

O/d was working fine. Then I got stuck. Put the truck in 4L and sounded like something was going to snap. Loud metal popping noise. I git pulled out, then my o/d hasn't worked since. Still no speedometer either

 

Fix the speedometer, and O/D will more than likely start working again as well.