Digital Instrument Cluster

Disconnect instrument cluster connector. Turn ignition on. Check for 12-volts between ground and Brown wire at instrument cluster connector terminal A16. If voltage reading is less than 12 volts, check for open in Brown wire (cruise control circuit). See Fig 1.

Fig 1: Astro, Safari, C, K, S & T Series Electronic Instrument Cluster Connector Terminal Identification
Courtesy of GENERAL MOTORS CORP.
If voltage reading was 12 volts in step 1, check for 12 volts between ground and Brown/White wire at connector terminal B17. If 12 volts is present, replace instrument cluster. If voltage reading is less than 12 volts, check for open in Brown wire circuit. It may be necessary to enter ECM diagnostics. See TESTS W/CODES TBI article in ENGINE PERFORMANCE section.