Need help 95 wca/wia engine codes

Are you sure it’s 9?
Not something like 1 flash pause 5 pause 3?
Maybe @BoxCarKidd is around,I think he used to work on those trucks.

 

I am with 062 about those flash codes. That is a Cummins thing. Sometimes you just need a scanner.
Problems I recall are a battery cable left off. I thank they all had 2 + and 2 - cables from the battery pack. They went to the starter ground and solenoid positive. Insulation worn through a positive cable on the frame or PTO?
The truck main power feeds connected to positive solenoid terminal. Botched up terminal ends on those from a previous starter replacement. Ground could do the same.
Loose grounds in the cab. If I have not confused them with another model there is a gob of white ground wires on a screw under the dash panel on each side. That would be near the outside bottom corner of each windshield.
More direct to your problem check the ECM power and ground wires at the batteries. Are the batteries moving around?
We had one with a Cat doing stuff like that. It ran regional but finally shut down coming to a light 5 miles from the shop. Volt gauge still worked and the starter would spin the engine over. Test light would light between engine and frame. It had no ground wire between starter ground stud, block and or frame. Seems it ran over 400,000 miles grounding through engine mount bushing bolts and or driveline.