Jake Brake Relays

[Flyfisher]

Chassis wiring diagram 1729813 rev EE for S60 DDEC III shows only K22A and B relays controlling low, medium or high Jake brake range selection. My bus also has K22C relay installed and wired into these circuits. I am having intermittent Jake brake problems and am trying to understand the circuits, but since K22C relay was removed from the drawing its a difficult task. An older drawing revision showing the original circuit design would be most helpful if one exists anywhere in a blue box. Does your bus have the K22C relay or does anyone have the drawing showing all three K22 relays? Any info in this area would be helpful.