Chrysler Repair: electronic instrument cluster: 87 E-body, digital instrument cluster, oil pressure gauge

Question
i have a digital instrument cluster in a 1987 Chrysler new yorker. it no longer lights up. i have no speedometer, gas gauge or oil pressure gauge, but the odometer still works.
is there a light bulb in need to replace or do i have to replace the entire unit?
thank you for your time,
JC

Answer
Hi JC,
It would be useful to check whether you have voltage to the circuit board and that the circuit board is properly grounded. Then if you do, let me know and there is a self-diagnostic test that you can do decide about the cluster proper. So remove the cluster and verify that you have 12V on pin 1 (red wire) all the time, and 12V on pin 6  (dark blue trace wire) when the igntion switch is in the run position, both of these pins are on the 13-pin conntector. Also, verify that the trace to which the pin is connected shows the voltage as there could be a cold solder joint. Then on the 21-pin plug make sure that pin 6 (black/light green wire) has continuity to ground, any shiny metal surface nearby. Again verify that the actual trace is continuous to ground. You can assess continuity using an ohmmeter which would show 0 ohm if there is continuity.
Then if you pass those measurement, write back and tell me whether your cluster has a tachometer or is it a traveler type cluster?
Roland