Great thing about the field effect ammeter is one can relocate the sensor easily. No moving the shunt, or cables required, just unbolt cable slide off round sensor and move to another cable.
Can also put it on the (+) cable, which is how mine is presently working.
Mine is still reading total alternator output, but at some point I will move it to read amps into or out of the battery(I already have this displayed elsewhere, not visible from driver's seat), with the display on dashboard, next to my 3 wire voltmeters, next to my turns counting 10 turn bourns potentiometer which adjusts the vehicle's voltage regulator to what I determine is best for the battery at that moment.
Buhahwahahhahhaaaaa.
Yes, than maniacal laughing you just heard way off in the in the distance, was me.