You might find this helpful The voltmeter with an internal relay has 3 wires coming out of the back. The Red and Black wires plug into the wires connected to the battery and the Yellow wire is used to turn the meter on and off.Simply connect the ring terminals to the correct battery post (Red to positive, Black to Negative), connect the Yellow wire to a switched 12V positive (such as the brown wire coming off the ignition switch), plug the red and black leads off the meter into the mating connectors and that's it. The meter will now come on when the ignition is switched to the on position and will read battery voltage directly.

You might find this helpful The voltmeter with an internal relay has 3 wires coming out of the back. The Red and Black wires plug into the wires connected to the battery and the Yellow wire is used to turn the meter on and off.Simply connect the ring terminals to the correct battery post (Red to positive, Black to Negative), connect the Yellow wire to a switched 12V positive (such as the brown wire coming off the ignition switch), plug the red and black leads off the meter into the mating connectors and that's it. The meter will now come on when the ignition is switched to the on position and will read battery voltage directly.

You might find this helpful The voltmeter with an internal relay has 3 wires coming out of the back. The Red and Black wires plug into the wires connected to the battery and the Yellow wire is used to turn the meter on and off.Simply connect the ring terminals to the correct battery post (Red to positive, Black to Negative), connect the Yellow wire to a switched 12V positive (such as the brown wire coming off the ignition switch), plug the red and black leads off the meter into the mating connectors and that's it. The meter will now come on when the ignition is switched to the on position and will read battery voltage directly.

Really accurate in reading voltage! It's easy to install and his style is awesome. Using it with a dimmer and it works great, a must have on contorl console! Thanks BG

Really accurate in reading voltage! It's easy to install and his style is awesome. Using it with a dimmer and it works great, a must have on contorl console! Thanks BG

Really accurate in reading voltage! It's easy to install and his style is awesome. Using it with a dimmer and it works great, a must have on contorl console! Thanks BG

very nice little instrument,at very low price.can use it on any DC device or vecicle project from 4v to 99v DC.as other customers said the red cable to possitive,the black cable to -negative and the yellow cable to possitive too(with a switch or not) .thank you banggood!

very nice little instrument,at very low price.can use it on any DC device or vecicle project from 4v to 99v DC.as other customers said the red cable to possitive,the black cable to -negative and the yellow cable to possitive too(with a switch or not) .thank you banggood!

very nice little instrument,at very low price.can use it on any DC device or vecicle project from 4v to 99v DC.as other customers said the red cable to possitive,the black cable to -negative and the yellow cable to possitive too(with a switch or not) .thank you banggood!

πολυ καλο . τελειο really good. wow could have a protective glass from all perfect thanks

πολυ καλο . τελειο really good. wow could have a protective glass from all perfect thanks

πολυ καλο . τελειο really good. wow could have a protective glass from all perfect thanks

Very nice quality Voltmeter. Will not operate below 5v, as the description says. Current consumption of the meter is less than 10ma. Display is nice and bright.

Very nice quality Voltmeter. Will not operate below 5v, as the description says. Current consumption of the meter is less than 10ma. Display is nice and bright.

Very nice quality Voltmeter. Will not operate below 5v, as the description says. Current consumption of the meter is less than 10ma. Display is nice and bright.

Хороший вольтметр с доп.питанием. Отлично подходит для различных DIY проектов. Яркий экран и удобный корпус. Цена просто отличная.

Хороший вольтметр с доп.питанием. Отлично подходит для различных DIY проектов. Яркий экран и удобный корпус. Цена просто отличная.

Хороший вольтметр с доп.питанием. Отлично подходит для различных DIY проектов. Яркий экран и удобный корпус. Цена просто отличная.

Good product as usual, fits in a standard switch hole. Good service great to deal with thanks Brian

Good product as usual, fits in a standard switch hole. Good service great to deal with thanks Brian

Good product as usual, fits in a standard switch hole. Good service great to deal with thanks Brian

It works perfectly, the minimum supply voltage is 4 V. Fast delivery to Europe. I'm buying another.fast delivery, good quality

It works perfectly, the minimum supply voltage is 4 V. Fast delivery to Europe. I'm buying another.fast delivery, good quality

It works perfectly, the minimum supply voltage is 4 V. Fast delivery to Europe. I'm buying another.fast delivery, good quality

Buen producto, tal cual sale en la imagenes. El precio en el mas bajo que he encontrado.

Buen producto, tal cual sale en la imagenes. El precio en el mas bajo que he encontrado.

Buen producto, tal cual sale en la imagenes. El precio en el mas bajo que he encontrado.

perfect for electronics projects or for installing on a car/boat dashboard

perfect for electronics projects or for installing on a car/boat dashboard

perfect for electronics projects or for installing on a car/boat dashboard