Garmin Ground Wire Fuse/CB?

[CharlieWaffles]

I am looking at the wiring for the Garmin GTN 750 and one of the diagrams (E-4) shows a fuse/Circuit Breaker on some ground wires. See the bottom three pins in this diagram. Is this just a typo?

[BobTurner]

Typo. No CB's on the ground wires.

[az_gila]

Yes minor typo on the bottom three wires. They just cut-n-pasted from the power lines.

The point they were trying to make was 20g wire for a 28V system and 18g wire for a 14 V system on both the ground lines and the power lines.

For the bottom three pins it should read

20 AWG (28 VDC system)
18 AWG (14 VDC system)

You should check what note 3 - the 3 inside the triangle - says though.

[CharlieWaffles]

Thanks, that's what I figured. Note three just says all power leads are needed.

[LeeM_2000]

This is not a typo. The C/B and voltage call-out helps you verify the ground wire is the correct gauge. This is just a way of reinforcing/reiterating the relationship between the wire gauge, volts, and current rating because getting this wrong would be potentially very bad.

[CharlieWaffles]

It must be a typo, none of the other ground wiring in this or other diagrams show a CB/Fuse. Sure they will show a gauge to ensure its the same as the power source, but the inclusion of the CB must be wrong.