Reducing voltage?

I want to install two cameras on an Aux switch. Each camera pulls 3-4 volts. I figure I need to cut off the 12v cigarette lighter plugs off each camera. Wire them in parallel with a fuse. But how do I reduce the 12v down for the camera? I figure there is something I should be able to order on amazon.

resister(s) needs to be soldered in line with the fuse.

Just google resister values and there will be tons of info on what you need.

And your basic understanding of 12volt electricity is a little off.

A device does not "pull" voltage. The voltage is what is required by the device.

the amperage is what is consumed, or "pulled" in your terms.

think of it in terms of water in a pipe.

voltage is the force the water is flowing, amperage is the amount of water flowing, ohms is the resistance (sprinkler head), that is the basic way i was taught as a foundation.