question

Since the 30A fuse is not blown, the Orion is not short - circuit.

This then leaves the -ve return as being high resistance somewhere. You should check all connections again, particularly by checking voltage from the battery negative POST, then if you find a dubious voltage, double check from the battery POSITIVE POST. Checking from the post removes volt drop across connections. Alternatively, measure from the Orion -ve input to the battery negative post, with the Orion plugged in.

I‘m confused. You’re stating you have inputs connected but where are your output going? What is your application (boat, van, etc)? On my boat I have the Orion smart 12/12-30 + and - connected to the + and - terminals of a single FLA engine started battery fused on the + side with a 60A MRBF, and the output side of the Orion Smart connected to the + and - side of 2 100AH Battle Born LFPs wired in parallel, again using a 60A MRBF at the positive side. The engine detection parameters were set up in Victron Connect and all works fine.

Thanks for the pointers.

It's for a van setup, the Orion is connected to two high current bus bars (one +, one -) through a 30A fuse on the +

The 150ah battery is connected to the same bars, through a 30 A fuse and a switch on the +, through the shunt of the BMV700 on the -

The first issue has been solved thanks to your guidance ! I tested the terminal in all points, turns out it was a poor connection under the (-) input terminal. Cut it, plugged it it worked !

I then struggled with the tiny wire bridge, as the app kept telling me that the remote control was off. A couple tries later I got it to work properly and it now display BULK charge when the engine is running.

However, there seem to be not current output? The BMV700 is not showing any current going in, on the contrary it shows a tiny consumption (-0,11A). All fuses measure ok. The output shows 12.9V as per the app.

Might try to run it in 12V supply with battery isolated later to see if it runs the lights.