Provided by Vince Cattolica, KA7JOI, Sept. 1, 2020
Some time ago I was asked by a new ham about how to install a mobile radio in his vehicle. My response to him was something like, do not use the cigarette lighter because the wiring and fuse to the cigarette lighter are, most likely, not designed to carry the load his transceiver will put on the circuit. I then suggested he run a separate circuit directly off the battery to avoid the problems that might arise by using the cigarette lighter socket. I suggested using a separate circuit for two good reasons. The first reason for powering his radio directly from the battery is that he can install and fuse a circuit designed to handle the current he will need for his radio. The other reason for running a separate circuit is that he can operate the radio without having to have the engine running.
Power Wiring for Mobile Radio Installations
The above article discusses the installation of a fuse in the “+” positive cable but doesn’t discuss putting one in the “-” negative cable. Here is some additional discussion of this topic.
One Fuse or Two; That is the Question!