voltmeter
1. If you pull out the ammeter, you'll need to tie the two electrical leads together, as it is a series device. Make sure these leads are well secured & insulated to keep the connection from shorting to ground. The ammeter might have an external shunt resistor (very low resistance -- almost a dead short) wired in parallel with it. If the meter leads were tied together, you can just leave the shunt in place. A voltmeter is wired in parallel to the main battery circuit, and is generally a high resistance device that draws little current. However, it does draw current when it's showing a voltage, so wire it after the main switch. 3. I'd suggest reading through one of the good boat electrical books on the market for specifics. N.Calder's "Boatowner's Mechanical and Electrical Manual", McGraw-Hill, is a good reference.
