Safe is to find a voltmeter as you know. getting one to fit in the original spot ...that might be tough. All I was attempting to do is explain the "theory" behind the "shunt". Not a recommendation, by any means. The issue only comes up for those that want, or need big current outputs. My truck has the original 2-20 A.C. That is 2 windows down and 20 MPH. An aftermarket radio does live at the bottom of the dash, but it is a small current item and fused. 35 Amps runs every thing I need. Added fuses are to the heater and wiper motor. tTat is about it. For the "hot rod" types, the way to go is the voltmeter, at least it is safe. A main line fuse on the Alternator is wise. There is enough ways to start a fire without adding one, so please be safe.
