Chrysler Repair: RPM/speedometer not working on a 97 Chrysler T&C, chrysler town and country, drb iii

Question
The RPM and speedometer on our 97 Chrysler Town and Country quit working altogether. In the beginning we could just turn the key off and back on to get them to work ... now nothing. Everyone seems to have an opinion by nothing has worked so far.

Answer
Hi Kathy,
I added the P.S. and evidentally that wiped out the original posting! Briefly, The data for the speedo/odo is carried on the CCD digital data bus along with the data for the balance of the gauges, so if the other gauges work it means that either the cluster is the problem or the data from the sensors for rpm and speed are not getting on the data bus. The data bus and the sensors can be checked with a DRB III, a Chrysler readout box, that looks at all the systems for faults. A dealer would probably be the best place for that to be checked out. But the cluster could have a common fault in the speedo/odo gauges such as a common ground trace on the circuit board or the ground for the whole cluster that is flakey. So you might weigh the options of looking for a used cluster at pull-it-yourself wrecking yard as opposed to spending more on labor at the shop. Or take out the cluster and look at the printed circuit board to see if any of the traces for the speedo/odo gauges might be cracked.
Sorry for the snafu, I'll send the site a note about that loss of message.
Roland



P.S. If the transmission is otherwise shifting as usual and no other problem appears to be present in the powertrain, that would tend to suggest that the issue is with the cluster rather than the sensors because the sensor signals are necessary for the powertrain to shift properly.