A likely cause is a failing instrument cluster.
Purchase or borrow the Mercedes cluster removal keys 9 bucks on eBay, and place them in the slots on the side of the cluster and pull the cluster straight out. Takes 2 minutes Get the cluster repaired in the USA for around $250
1. disconnect negative battery cable and wait 2 minutes (this disarms the airbag circuit while you work in that area). Remove the left end cover by pulling outward. Tilt steering column down to lowest position. remove instrument cluster center bezel (around radio and environmental controls) by disengaging 4 clips (2 on top and one on each side). 2. Remove 4 instrument cluster hood mounting screws. Three screws are located behind the center bezel and one screw is located at the left end of the hood. Pull on hood to disengage hood and remove instrument cluster hood. Pull instrument cluster rearward to disengage 8 clips and disconnect wiring connectors from panel. Remove instrument cluster.
I had read that what you have to do is after you replace the cluster try to start it once. Leave the key in the on position for at least 10 minutes and that is supposed to reset the anti-theft system and it should start and run fine.
I had the same problem with my 1998 Dodge Ram 1500. I reseated the instrument cluster and it started working. The whole thing took me 15 minutes and I am not a mechanic. I believe that I removed three screws to enable me to remove the plastic which covers the instrument cluster. I can't remember how many screws hold the cluster down but once you remove them pull the cluster out. It is simply plugged in, and those connections are your problem.
Disconect the battery for a few minutes!
the problem is the guage cluster itself and should be replaced with new one from a Chrysler dealer *Thanks Dan, but instead I unhooked the battersy for 5 minutes to reset the computer and now it all works perfect.
Unhook battery for 5 minutes.
I have an 05 impala and had problems with the speedometer and fuel gauge. The only way to fix it was to replace the whole instrument cluster. Pretty easy to do, only took about 45 minutes.
pull on the little knob on the instrument cluster until the clock flashes. adjust (left and right turns) with the knob. keep pulling it to change the hours, minutes, and eventually the calendar.
Did you check for a leak?