The Plug-In voltmeter gives you the ability to monitor your vehicles electrical system. Plug voltmeter into cigarette lighter socket or power point socket. Make sure the voltmeter is plugged into the socket completely to assure good contact.
When the engine is turned off the voltmeter will display battery voltage. After engine is started, the gauge will display alternator output. (note): On some vehicles it may be necessaryto turn the ignition switch to "on" or "accessory" position for the power points or lighter socket to receive power.
If the voltmeter does not fit your lighter or power point socket, you may be able to purchase an adapter from your local parts store.
