Volt meter problem

[Scott71]

I have a 2008 Drive electric. I purchased a Yamaha volt meter to add to the cart. I installed it per instructions but the voltage never shows to drop. When the cart quits the meter is still showing full charge. I verified the meter was 48 volt. I then tried a Hobbs meter and it does the same thing. I am using 14 gauge wire with the positive wire going to main positive terminal and negative going to main ground on opposite battery. I recently replaced the Trogan T1275 batteries with Exide group 31 deep cycles. Any thoughts???