Digital dash readout is blank

Visit the on-line store, know as reliable-store, they have the repair manuals. I'm sure you will get the solution of your problem.
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Are you saying it won't crank, or won't start ?
And have you checked the alternator output when the engine is running ?

Either your Fuel Sending Unit is bad, or the Instrument Cluster is bad

You are going to need a new or used dash cluster it is a digital readout and is not repairable by replacing bulbs

This was a fairly common problem with the early digital dashes and I believe the problem was with a circuit board inside the dash itself. A poor connection or crack in the circuit board would cause a loss of all the digital readouts and often the problem would come and go at random. There are some companies that repair these and other digital readout dashes so I would do an online search and contact a repair facility that specializes in this. I've never found anything that can be done to the outside of the dash [connections, etc] that would help the problem. Good luck, hope this helps!

Try disconnecting the battery for about 10 to 15 minutes and reconnect. See if that helps.

Mike.

apart from the vss there is another speed sensor on the transmission. (counter shaft speed sensor)its a 125 dollar sensor.
hears a pic.

Remove the instrument panel form the dash. Pull the back off and resolder resistor R13 on the back circuit board. This is a fairly delicate job and requires a fine pointed soldering iron. This fixed the Tach, Odometer readout, and fuel guage but not the speedometer in my 85 900 s.

Any ideas on the speedometer?

check your fuses it might just need a new 20 amp fuse which is a little "U" shaped yellow thing

I am currently working on my 92 Deville with the same problem. I was driving along, and smelled what I felt was a smoking printed circuit board. I looked down, and the digital fuel data center and climate control panel were dark.

I have the factory shop manual, and with the aid of a meter and the manual, I traced the problem to a bad BCM. The 16v supply coming from the BCM was gone. Opened up the BCM and found an overheated transistor. I also removed the fuel data center and the Climate control panel. The fuel data center panel did not smell good. I found a shorted capacitor on the Fuel data center circuit board. I am replacing the capacitor, and will be picking up a used BCM at the boneyard tomorrow. I might also have an overheated wire in a cable that might have to be replaced. I have not gotten that far in the troubleshooting yet.

Good luck with your problem.......