Was looking at the little black box for ages before finding it on google (speedo adjuster)... and the use of double core insulated wire, and the block of piggy back connectors... did a voltage test to try to trace back things, popped 4 fuses. Black/Orange to ground knocked out the driving lights and "Lights on" accessories (which expected), Black/Blue threw the lighter, the accessories, and the driving lights...
pulled it all out, started again... didnt have the wire to run a new line from the fuses so still stealing from the lighter as before.
Also a while back figured out why the siren wasnt working on the alarm system, battery in it was fine, there was a broken wire under the dash, one of the clips were cable tied too tightly and had a broken connection... you could tap it and the siren would click as the circuit was made... clipped the clip and soldered the wires together.
Now if i could only keep it clean, such a dirt magnet