[jmeckel]

Better to hook to the frame ground point,where the ground strap from the battery connects. You never want a path through other electronics to the battery that is better than the path that the starter uses. If you do, the starter will try to "pull ground" through those other devices and there will be smoke... I would also add a #2 or larger wire from the same ground point to one of the bolts on the starter while you are at it, not hard to do and can really help with the starter issues if the existing path becomes poor.