Its an LEM HAS 200-S. supply voltage +-15v, output 0v reference and +-4v for +-200A of current flowing.http://parts.digikey.com/1/parts/945568-transducer-currnt-open-loop-200a-has-200-s.html
I verified (in-welder) that the supply voltage is good (30v) and the output just isn't there, so I ordered off for a new one.
The hall effect device costs $25, a new control board (the other thing that could be horked) costs $650. and I'm pretty convinced
its the hall device now anyway.
after looking up the specs (once I realized it was not a proprietary part) I now know I could just stick it on the starting battery cable for my truck and wire up +-15v and see what happens on the output when I crank over the engine. (its a little to small to stick it on one of my EV's battery cables, but it would fit a normal starting battery cable)
On an aside a unit similar to this one might make a good pickup for a watt-hour meter and ammeter or what have you in an EV. total isolation. Is that what the fancier things use (e-meter, paktraker, etc) or do they use a shunt?