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My stupid electrical question of the day...
Posted: Thu Jun 13, 2019 10:33 am
by TheSaintDiscJockey
Okay. Other things have come up this spring and have not devoted too much time to the T in the past month or so. I have been nibbling around the edges on my magneto horn, but want to get a question resolved. If I run a ground wire from the horn to the frame, will I screw up the magneto in any way? The horn works. The magneto works, but when I run the T on magneto and connect the horn to the terminal, the engine cuts out. I'm thinking the horn is not properly ground? It has the one post.
My knowledge of electrical matters can be placed on the head of a pin, with space left over. I just don't want to inadvertantly damage the magneto. The magneto runs on AC. If I can't resolve this issue, could I run the magneto horn on an independent AC source?
As always, I thank the forum members in advance.
Re: My stupid electrical question of the day...
Posted: Thu Jun 13, 2019 10:51 am
by Mark Gregush
To the first question, no because it has to be grounded in some way, the wire would work. Are you sure it is a magneto horn? Even the battery type only has one terminal. Are you trying to op the horn at idle speed(low mag output) or the horn could be shorting out so the output from the mag is taking the easy path to ground. Time to get the meter or test light out and look for shorts.
Re: My stupid electrical question of the day...
Posted: Thu Jun 13, 2019 10:54 am
by tdumas
The horn is grounded through its mounting. Your problem is an internal short in the horn.
If it was not grounded, it would not short out the magneto like it does.
Re: My stupid electrical question of the day...
Posted: Thu Jun 13, 2019 11:06 am
by cdromtom
You could also have a short in your wiring to the horn from the switch. Check for frayed or damaged wiring.
Re: My stupid electrical question of the day...
Posted: Thu Jun 13, 2019 11:12 am
by Norman Kling
You say,"Connect the horn to the terminal". To which terminal do you refer? There should be a wire from the magneto terminal to the horn button and another wire from the horn button to the terminal on the horn. The horn would then be connected to the magneto only when you push the button.
Presuming you have the correct horn and it is in good working condition, and the magneto output is good, honking the horn should not kill the engine, however a direct ground to the magneto terminal would kill the engine. It would not damage the magneto. A direct ground could occur if either of the wires are grounded (short to ground) or if the horn is shorted internally.
Another possible cause would be a weak magneto. Usually a weak magneto would be indicated if the engine runs OK at speed but will not idle on magneto.
Norm