Never straight forward

So I’m confused… many who know me would say this is easily done!

Yesterday, I cut all the cable ties and laid out the loom. The plan was to collect the wires into their circuits, separating out those that won’t be needed.

The BCU came with a pin out diagram, basically a spreadsheet listing the function, colour and pin position of each wire. I used this to label up the loom and it seemed correct. The colours of the wires matched their pin positions on the diagram.

The BCU also came with 30 pages of wiring diagrams. Here is where the trouble starts. The wiring diagram also gives the colour of the wire and it’s pin position too. However, these don’t match the pin out diagram! There are some clear mistakes. For example, where a wire is identified on the wrong connector but the correct pin position. This is not that hard to identify. But there are some much more difficult to work through.

The wiring diagram doesn’t give the name/function of the wire so this makes it really challenging to identify which wire in the loom the diagram is referring to. After a couple of hours I’d sorted out the circuits for the daylight running lights (something I don’t currently have but would like to add), reverse lights, hazards and indicators, and an auxiliary circuit.

For these circuits I was able to work through the differences in between the pin out and wiring diagrams with a degree of confidence. Then I hit the ignition circuit. The pin out and wiring diagrams are not even close. There’s a chance that I’m misreading something as the wiring diagram is complex. By necessity it needs to show multiple different ignition options. However, I’ve only been able to find one wire where the pin out and wiring diagrams agree!

I’ve given myself a little space to let things percolate… hopefully when I get back to it this evening or tomorrow, the way forward will seem more obvious!