Puzzle, puzzle
Well, first of all, forget the suggestion about the coolant leak. The coolant goes, among other places, through a radiator that’s grounded to the frame.. if the heatsinks weren’t isolated, we’d have had troubles from day 1.
The idea that this is a problem with the rotary encoder is a little nutty as well.. when the drive is in neutral with forward selected, and it’s in cogging mode, it will also spin the motor about 400 rpm. Actually, the amusing thing is that when the drive is broken, it acts exactly like a ICE – it cogs (i.e. delivers power in little pulses rather than smoothly), it idles (i.e. spins the motor even when it’s not doing anything).. it even *sounds* like a ICE.
I would think this was a mechanical problem, but I don’t see how that explains either the inverter fault codes or the tendancy to spin the motor at 400RPM when forward is selected and the car is in neutral. I’m wondering, could some of the switching signal be being inductively coupled into the motor data wiring? Failing that, could I have overwritten some key parameter when running SIADIS from a corrupted disk? Uncommanded power output sounds suspicously like a software problem. I’m glad I opted for the EPO switch.. maybe I should test to make sure it still works..