steering wheel control panel

My Olds 98 Touring Sedan ( 1989 year ) has a problem suddenly with the control panel in the center of the steering wheel. None of the controls are working. The right side controls are for adjusting radio functions. The left are for heater and A/C controls. I pulled it apart and don't see any physical problems like loose wires or anything obvious. I'm not sure what voltages should be found at the five wires that provide power to the circuit board. If anyone has wiring diagrams or servicing info for this circuit I would very much appreciate your help. I checked fuses in the fuse box but none seem to relate to this circuit and all appear OK.

Is this circuit fused? Where does the wiring harness go to? The main computer?

Any help would be appreciated.