How to bypass start Volvo MDI Black Box on D1-30. SV CATAMANTOO 2022

Volvo MDI (Mechanical Diesel Interface) Black Box on a D1-30 failed shortly before we were due to launch.
Tried 2 old boxes without success.
Used a momentary on switch between +12v and starter solenoid terminals. Saved the day and easy to do. Engine stop is with the lever on the mechanical diesel injection pump.
The MDI Box monitors oil pressure, revs, water temperature and charging. Allows energising of the glow plugs, starter motor and fuel shut off solenoid. It also provides CANbus information to the instruments and engine hours. Thus the engine can run without it, but will be unmonitored. Starts fine without glow plugs.
The external start switch worked as expected. The wiring harnesses were plugged back in and we appear to have full monitoring via CANbus (rpm, engine hours etc). I have sent an enquiry to the Volvo agent for a new MDI Box - but at least were mobile on launching.
Excellent description of the MDI Box can be found here -
nordkyndesign....

[@PittwaterMowing]

Thanks for sharing Probably best to keep a remote switch in place for future failures

[@moomin110]

I had to do this! Bought a new mdi but left a switch like this in place incase that creams in too!

[@daha7864]

Nice, thanks. Now if I can just get fuel to flow through in mine, I can launch

[@SV-WAKAWAKA]

Hi - I hope you are successful. I have a 12v fuel pump & an outboard type squeeze bulb on the supply side - useful for priming the fuel filters and reinstating fuel if I ran out.
These engines cope with air well, never had to crack injector feeds.

[@daha7864]

I did get it to start using it’s primer pump; but, did have to crack all lines, starting from the injector pump outlet, until fuel flowed through them. Then crack them at the injectors and wait until fuel flowed through #1 without bubbles (once I finally got fuel up there). Once she started I recracked the lines at the injectors to get straight fuel out of the lines. Then she purred like a kitten after sitting for 8 years. 👍🏻👍🏻

[@cameroncollins9241]

thanks for vid, did it end up being a faulty mdi?

[@SV-WAKAWAKA]

No - I had lost a negative wire when putting a circuit breaker & bus bars on the Starboard engine battery.
Identified later, reconnected and all working again.