[folivier]

Here's what I have in the rear electric compartment. 2 heavy red cables with the smaller black wires (why black?) going to 2 small black unmarked blocks with a red wire & black wire on each. The 2 red wires go to the front of the rear electrical panel and are marked as ammeter on a terminal block, then go towards the front. So I assume these are the 2 red wires on the ammeter gauge. With ignition off both red wires at gauge have 12+volts, other 2 wires have 0 volts. With ignition on both red wires have 12volts, orange has 12v, brown has 0 volts.
At the back with ignition on all terminals have 12v.