Why are you doing this type of hook up ?
Just find a hot wire that has power only when the key is on or in Accessory then wire your CB to it, as above Fuse Tap posting.
Two things, one is that a lot of CBs have digital switches and if the power is removed they will shut off some don’t so chk out what you want or need first. If you want the CB to be on when you turn on the vehicle then watch what you buy.
Second is that even if you left the CB on all day long it will not drain a good battery, even without the engine running.
If you want to run a separate power wire for the CB, which is a good thing to keep noise out of the system, you could use a relay hooked up to an ignition hot wire and when the engine was started it would trip the relay and wham bam the CB will have power.
4x4, 5sp, Std Cab, Stepside, E4 Red
4” Lift - Coil-Overs, 6” SkyJacker Leafs - No Blocks (Mistake)
31 Spline FX4 Rear Axle, 4.56s and OX Locker, Hurst Shifter w/Optional Stick and "Made by Grev" alignment adapter