Pmag wiring question

This may be a dumb question, but no where did I find any explanation of changing the toggle switch wiring when I installed the Pmag. The old plead from the right mag is supposed to be grounded in the off position. If I used a toggle switch for the old magneto, do I just ground the switch to the frame or run a new ground wire? Confusing

You can use a toggle switch for the PMag also, grounded in the off position, but run the earth to your common earth point rather than just the airframe.

rwarre said:

This may be a dumb question, but no where did I find any explanation of changing the toggle switch wiring when I installed the Pmag. The old plead from the right mag is supposed to be grounded in the off position. If I used a toggle switch for the old magneto, do I just ground the switch to the frame or run a new ground wire? Confusing

Click to expand...

Cheers

Eddie

I'm interested in why a P-Mag requires the P-Lead ground to a "common earth" rather than just the airframe? If only because ours are just locally grounded near the panel.

The P-Mag ground itself - yes, needs a good ground since it is power, and ensure each P-Mag is separately grounded to avoid a single failure point - albeit again, ours are grounded locally (to the engine).

Just use the existing wiring. The P-mag P-Lead (P-mag pin 4) is ungrounded for running, so it shouldn't cause any noise issues. If you have an issue with noise, you can always move it later. Mine are grounded to the forest of tabs on the firewall, but that was with a new build.

The P-mag does required an electrical ground (P-mag pin 1) and it is this ground that SHOULD go to an engine case bolt. Do NOT ground this wire to the forest of tabs on your firewall!

Hi Andy,

Just trying to ensure that the ground is reliable, and in my case the most reliable point to ensure a good earth was to take it back to my forest of tabs.

Andy Hill said:

Eddie

I'm interested in why a P-Mag requires the P-Lead ground to a "common earth" rather than just the airframe? If only because ours are just locally grounded near the panel.

The P-Mag ground itself - yes, needs a good ground since it is power, and ensure each P-Mag is separately grounded to avoid a single failure point - albeit again, ours are grounded locally (to the engine).

Click to expand...

Cheers