The purple wire comes from the relay/resistors according to fan speed selected. The purple wire should have battery voltage ~ 12V when on hi. At low is might have 5V, M1 7 ish, and M2 9 ish volts. (note mine is not working and I think resistors are bad I get 11.9V on hi 11.73 v on all other speeds lo, m1, and m2.
Anyone ever measure what voltages are normal to speeds ?
Uhhgg I was interpretting measurement wrong in my mind. I was probing purple wire to black and expected voltage drops at different resistors ie speed settings. But with out current flowing through circuit voltages would not drop. V=ir ; no i then no V drop.
Anyway something funny was going on cause new resistors pk shows the same voltage lo - thru hi and OE was different Lo-M2 vs hi and they should all be the same with no current.
Anyway I have my fan working correctly again. It apparently was my motor and maybe my resistors too.