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Grounding left mag for start

togaflyer

Well Known Member
So I have installed a Surefly e mag on the right and have had a Bendix impulse mag on the left. I have an ACS 510-2 start switch. I wanted to ground the left mag (Bendix) during the start and let the Surefly do the start, so I ran a wire from the ground (Jumper side for the right mag) to the left mad terminal thinking it would ground the left mag and leave the Surefly on the right to fire. Nope. Instead it grounded the Surefly on the right side and kept it grounded. So is there a way to ground the left mag and let the right mag fire with this type of ignition switch?????
 
So I have installed a Surefly e mag on the right and have had a Bendix impulse mag on the left. I have an ACS 510-2 start switch. I wanted to ground the left mag (Bendix) during the start and let the Surefly do the start, so I ran a wire from the ground (Jumper side for the right mag) to the left mad terminal thinking it would ground the left mag and leave the Surefly on the right to fire. Nope. Instead it grounded the Surefly on the right side and kept it grounded. So is there a way to ground the left mag and let the right mag fire with this type of ignition switch?????

https://acsproducts.co/wp-content/uploads/2013/10/Wiring-Diagram.jpg

I think you used the wrong GRD terminal...

IIRC, the GRD terminal at the center (Terminal 5) is always connected to Ground, and GRD next to Terminal 1 is ONLY connected to Ground when the Key is in the start position.
 
Brian this is what is weird. I used the terminal ground that is normally used for the jumper ground to the right mag (where the jumper bar would be attached) and instead ran a wire from that jumper ground terminal to the left mag terminal. So my thought was it should just temporarily ground the left mag which is my Bendix impulse mag when you go to start. But instead it still grounded the right Surefly e mag on start. The Surefly remained grounded until I removed the jumper wire. Even when I set the ignition switch to the right mag position, the Surefly would not activate (no LEDs) until that jump wire was removed from the left mag terminal. I did not run it from the center terminal 5 ground. It must just be something internal with the switch itself I guess?
 
I don’t know how to fix the keyed start switch to make it do what you want, but if you can’t figure out how to do it, you might be able to remove the keyed start switch and install two toggles switches for the mags, and a push button, or keyed momentary switch to engage the starter. That way you can start on whichever ignition you want, or better yet - both of them.
 
Brian this is what is weird. I used the terminal ground that is normally used for the jumper ground to the right mag (where the jumper bar would be attached) and instead ran a wire from that jumper ground terminal to the left mag terminal. So my thought was it should just temporarily ground the left mag which is my Bendix impulse mag when you go to start. But instead it still grounded the right Surefly e mag on start. The Surefly remained grounded until I removed the jumper wire. Even when I set the ignition switch to the right mag position, the Surefly would not activate (no LEDs) until that jump wire was removed from the left mag terminal. I did not run it from the center terminal 5 ground. It must just be something internal with the switch itself I guess?

I'd suspect something is not quite right with that switch...

Check the behavior with an ohm meter (continuity checker), then reach out to ACS...
 
Why ground the left impulse mag at all during the start? Let them both fire! Typically you ground the non-impulse mag to prevent kickback, but with the left impulse mag, it should be fine to allow it to fire while starting. Right?
 
Correct.......

Why ground the left impulse mag at all during the start? Let them both fire! Typically you ground the non-impulse mag to prevent kickback, but with the left impulse mag, it should be fine to allow it to fire while starting. Right?

If the left mag is impulse, there's no reason to disable it during start.
 
I pulled the jumper I had installed off and the engine fired up fine. Mostly, out of curiosity, I wanted to disable the impulse mag just to test the start using the Surefly alone, then letting them both fire so I could see if there was any noticeable difference. Especially during a hot starts. I do plan to call ACS this week and ask them about the start up grounding just to make sure my ignition switch is working properly. Thanks all.
 
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