I have a 2003 Dakota 4.7. The gauges in the instrument cluster started going nuts every so often. At first only when it was cold out side and as soon as the heater warmed up it worked fine. Over time the cluster is working less and less. The seat belt warning light comes on and the audible alarm goes off when the seat belt is buckled. When the seat belt in not buckled and fully retracted the light goes off and the alarm stops. When the cluster is working and I do the self test it is fine. When the gauges go crazy the trip counter resets to zero. I have had the cluster out a few times looking for dust or anything on the circuit board. I am going to try the wires before taking it to the dealer ship. Any other ideas?

 

check to see if there is a ground for the cluster assembly.i had the same problem with an international tractor once and it turned out to be the ground wire was corroded.

 

I took the cluster out again and checked all the wires. I could not find any thing loose or corroded. The only ground wire that I see is at the bottom of the drivers kick panel. There is 7 or 8 in one terminal. I took it off and every thing looked good. I put the insrument cluster back in and reconnected the battery. The cluster worked fine and the instrument test was fine. All the lights are out except the seat belt light. It goes out when the seat belt is not connected and comes on with the belt connected. After several minutes the gauges go crazy for a few seconds and then back to normal. I am not getting any codes right now but in the past I will get P1687 after the truck sits over night.

 

Check other grounds. Might be a very close to loose one by the battery. I pulled my bulb out on the drivers side knocked a wire (ground) and it starting going haywire. It would turn off while driving no lights nothing. Just check it. But Mine gave me codes never any for ground. Maybe your pcm is shot? I would take it to the dealer or something.

 

Where is the ground for the instrument cluster?