Chrysler Repair: 1993 Chrylser Concorde Instrument Gauges, powertrain control, xerox copy

Question
The speed, tach, fuel and water temp gauges have stopped working. They momemtarily stopped working a few times and restarting the engine fixed them, but now they are not working.  Everything else in the car is and it drives fines.  All of the display lights are lit, just the gauges have stopped.  I've checked all of the fuses on the left side of the console and the bank on the driver side immediately behine the battery under the hood. Any idea where the common power link brances off for these gauges?  I assume that's what it would be.  

Answer
Hi Jack,
I know the general reason for the all the gauges not working. They all rely on digitized signals that come from the various sensors to a central data handling bus called the CCD bus which is a two wire twisted pair that connects together the powertrain control, the transmission control and the body computer and shares the data for the fuel, temp, tach and speedo with the instrument cluster. The data comes into the cluster on the black plug and the wires in question are the ones that are twisted together. The issue could be at the connector, or in the wires along the bus, or possibly a ground wire at the instrument cluster (though I can't be sure if that being flakey would only take out those 4 readouts). The fact that the rest of the car is not impacted suggests to me that the place to start would be the cluster plug (check all connections of the black plug) and check the continuity of the CCD bus wires (pins 3 and 4 of the cluster plug to pins 4 and 3 of the data link connector under the dash (6 pins) next to the steering column which is the most easy access to the bus system and which if you found "open" would prompt a search for a break in the wires to the cluster, and then if that doesn't correct it get a used cluster from a pull-it-yourself wrecking yard. If you don't have a Haynes manual or similar that shows how to access the cluster I can send you a xerox copy of the procedure from the shop manual. Just send me a postal mailing address.
Roland