E-Mag Wiring

Time: 2 Hours

Another firewall forward wiring task was to finish up the E-Mag runs. This is my engines ignition source. In traditional Lycoming engines they use magnetos to provide the ignition source. The E-Mags use newer technology to control very precisely when the spark is delivered in reference to pistons compression stroke. Another benefit is they have their own internal alternator that provides power for the spark even if all ships power is lost. For these reasons I went with this setup. There are only four wires needed to go to each E-Mag, a 12 volt source, a ground, a p-lead and a digital tach reading. The 12 volt, tach and p-lead I had run a while ago so I just needed to add a ground to the mix. I made the appropriate extensions to the wires and figured the best path to run the wires to the E-Mags. They have a connector that plugs into the back and you just have to screw each of the wires to the connector. The 12 volt source provides power under normal operations, the ground provides normal ground and the tach will give me an RPM reading. The forth wire is the p-lead for testing the function of the E-Mag using a switch in the cockpit. In normal operations the power is providing spark using the ground of the engine with the p-lead switch(I labeled it ignition) in the on position. When you put it in the off position you are grounding the p-lead and denying the E-mag from creating spark which only allows half of the spark plugs to operate making the engine run rough and providing a positive test that the E-Mag is working when the ground is removed. The last test for the E-Mag will be to remove the 12 volt power to make sure the internal alternator operates. I will do this by turning the circuit breaker off on my Dynon screen. After running all the wires I secured them and plugged in the connector. If I did them all correctly when I put power on I should see a red LED followed by a green LED. My luck was good and that’s just what happened!

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