you want to see battery voltage @ the red 12v plug at the distributor. ideally the same as what you are reading at the BAT terminal. ie: 13.8Vdc,not 13.5 or 12.9,etc. if readings are identical this means there is no voltage drop which is what you want. if readings are not the same this means you could have a bad connection, undersized wire, resistor wire, bad distribution, etc