Was it a paddle wheel? If so, I'd think any paddle wheel would be ok, it's probably just a hall-effect sensor, not unlike the crank position sensor on your car engine. That said, I'm baffled by the shorting out of the whole dash by that part breaking off...
Does it look like this:
http://www.ebay.com/itm/FOURWINNS-BO...-/201436318586 and this:
http://www.ebay.com/itm/FOURWINNS-BO...3D201436318586