It depends. I use Dynon and all the avionic boxes use very low current. I use a terminal block similar in the picture. One side takes in the bus power from a fused or circuit breaker, and the other side provides electrical output to the rest of the support avionics. The only downside is if the bus power goes out, the rest of the avionic goes out too. Some people have a dedicated power wire to each of the unit. Simple saves weight at the cost of redundancy. More complicated means more weight, more wires, but gives you more granular control.what is the best/correct way of connecting power wire’s together. Have the Garmin components(Gea 24, Gap 29, etc) that all need power. Can I splice them together?
I 2nd this. Both points.Suggest you read Aeroelectric Connection by Bob Nuckolls as well as Aircraft Wiring Guide by Marc Ausman. Aircraft Wiring & Electrical Installation by Avotek Information Resources is also a good source. BTW, circuit breakers are intended to protect the wiring, not the electrical equipment attached to the wires
+1I recommend a separate fuse for each load. If a fuse blows, you won't have to guess which load is the problem. Fuse block(s) including fuses might cost less than one circuit breaker. And fuses are lighter weight and easier to replace than circuit breakers. Van's sells lighted fuses that glow when blown (provided that a load is connected). Never replace a fuse or reset a circuit breaker in flight. How often to you replace fuses in your road vehicle?
The simpler the electrical system, the better. Yes, there is an alternative to an avionics bus: Just one main power bus with all loads connected to it. If an avionics switch or relay in not installed, then it can not fail. Read what Bob Nuckolls has to say about avionics master switches. Avionics Master Switches: Really Necessary?
A/P is integrated into the EFIS, so there's that. Servos have the A/P disconnect button on the stick (true, doesn't remove power from them, but they can be overcome by moderate stick forces anyway, like any well-designed A/P servo-aircraft system).Fuses are fine for protection of the wire to each device, but with circuit breakers you gain the ability to pull the breaker to turn off the device (or devices) connected to it. There are a few of my devices that I want to be able to interrupt during flight, like the autopilot and AP servos.