Sadly the compartment directly below the slide is a welded steel box next to the engine, only thing in it is my tools, the next compartment forward is the DEF tank open to the outside, no compartment aft of the slide. I did however look into both to double check, no joy.
Tomorrow I’m going to try and trace cables, open the back etc, I’ve got one of those cameras on a flex shaft and will see if I can trace cables before I start pulling stapled walls loose, everything around that slide is very tight on the inside and behind seals on the outside with no visibility behind them..
You would think that controller would be accessible but so far no luck.
Jeff