It's official.....I don't understand car electrics, especially when everything is controlled by 'modules'.
I wanted to wire in my new wiper motor yesterday. I have three wiring diagrams; the BMW diagram, the one that came with the (generic) new motor and an old picture from DNA just showing wiring colours to the new motor's plug.
Firstly I wired the motor in the same way as the original BMW one (it's a two speed motor with a built-in 'park' switch, how could it go wrong). Nothing. Didn't work at all.
So then I went with the diagram supplied with the motor and worked out what does what on the connections. Nothing. Didn't work at all.
I looked at the DNA diagram last, as there was no detail, just colours to terminals. The colours were wrong on their diagram (ie they said a 'black wire' whereas the actual colours were black/red/yellow and black/white/green), but I made an educated guess as to which ones were which.
when I wired it up to their diagram, I looked again at the BMW diagram and it seemed to make no sense whatsoever. So I gingerly put the ignition key in and turned the wiper stalk, fully expecting a 'bang' and it taking out half the fuses on the car.
Worked perfectly!! It does EVERYTHING the BMW original did; intermittent, slow (intermittent at rest), fast, three wipes for wash, the lot.
BUT I have no idea how or why it works which really frustrates me, as I like to know HOW stuff works not just that it does.
I can see I'm going to have fun when it comes to re-wiring the dashboard and all the switches!