Mitsubishi challenger pinout diagram for instrument cluster

Loss of communication with the ECU is a possible cause.

Question edited for clarity.

Try these

https://portal-diagnostov.com/en/2020/04/11/instrument-cluster-ford-econoline-e150-1998-system-wiring-diagrams/

https://www.google.com/search?q=2000+e150+4.2+van+instrument+cluster+pinout

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Check out this post telling the reasons the speedo is inop.

https://repairpal.com/mitsubishi/diamante/speedometer-not-working

The first thing you need to do is have the transmission control module scanned for fault codes.

You have so many problems but not much to work with. Let's try something to help you out.
1. Instrument panel is it Analog or Digital
2.For speedo and tach do you have a speedo cable attach to the cluster?
If it's with speedo cable. Inside the transmission, there is a plastic gear could be worn. And the cable at the cluster's end could be stripped or not install properly.
If it's with the digital cluster the speedo works with a buffer module near the glove compartment (It convert the analog signal to digital signal for a digital cluster.
I could tell you more but need too many info.
There is many instrument panel depends on the options.
See options: links

Hope it helps.




Find out instrument panel pinout (or electrical diagram) for wires testing.

1. There is more ground than only one and there more + wires at cluster panel. I will have to check those circuit and finally find the problem.

The Instrument cluster is partially burnt ....this is caused by the thin metallic strips that are part of the cluster.....It is designed like a road map ...the paths will lead to each gauge or light and sometimes burnout in a few places rather than all areas.....they can be replaced by removing the instrument unit and it is mounted to the back of it......I really need to know the year make and model...or just last 9 digits of vin #.I might can help you find one or an entire assy at a cheap price guaranteed.....

If you can remove the cluster ... light bulbs are fitted to sockets that rotate out of the cluster. A blown bulb usually has smoked glass from the blowout depositing metal on the inside of the bulb.

Try moving a working bulb to the speedo and tachometer, and of course replacing any blown bulbs with the same from a parts store.

If using a new bulb does not work in the speedo/tach, look for a blown fuse in the fuse panel. Look at the two(?) female cluster connectors on the back: remove any green corrosion/dirt with WD40.

If you have a multimeter, trace the speedo/tach circuits from the cluster connectors to the bulbs and hence to ground. There could be a crack in the flex circuit.

If the problem persists, there's a more problematic issue in the wiring harness.

Could be that speedo cable has become disconnected or that the inner shaft has broken. The speed cable is connected between the back of the instrument cluster and the left side of the transmission. Check under the car that the cable is securely fitted to the side of the transmission. Disconnect it and and check on the condition of the square drive flexible shaft. The spinning of this inner shaft is what conveys the output shaft speed of the transmission to the instruments. The instrument cluster can be removed but pushing a length of coat hanger wire with right angle turn on its end between the the cluster and the dashboard surround. Turn the coat hanger to hook behind the cluster and pull forward to remove it. Try several points around the cluster. It is best to disconnect the speedo drive cable to withdraw the cluster (after electrical connections have been disconnected. check that the speedo cable is secure to the back of the instruments. If you remove the cluster completely follow the path of the speedo cable. If you have to replace the cable, tying a length of string to the speedo cable end first and posting the string down the cable path will help the re-installation enormously. Simply pull the string whilst reinstalling the instrument cluster until the end of the speedo can be got hold of. Refit the speedo cable to the transmission only after the instrument cluster is back in place.

they sell a speed sensor that plugs in to your trans that controls the speedo I would try that you can get it from any after market auto parts store

Has it had an aftermarket Stereo Fitted? This is the first place I ould look if it has..