Coi + wire has 14 volts at idle, why???
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From: NY
Car: 88 firebird
Engine: 355
Transmission: t-5
Axle/Gears: 9 bolt 3.91
Coil + wire has 14 volts at idle, why???
I recently installed an MSD 8920 and I powered it through the original coil positive wire. I'd like to know why the coil positive wire would have 14 volts running at idle. I'm pretty sure this fried the 8920, but the MSD guys don't think so, and they repaired it for free.
I'm guessing the original owner used a wire he wasn't supposed too for the coil positive.
When I had a stock hei setup I never had any trouble running the coil off this wire.
ONe more question, why when I turn the key on, I can hear a high pitched noise coming out of the alternator, other than that it works fine, I never noticed it in my last thirdgen, and I used the same alternator?
It's not that loud.
I'm guessing the original owner used a wire he wasn't supposed too for the coil positive.
When I had a stock hei setup I never had any trouble running the coil off this wire.
ONe more question, why when I turn the key on, I can hear a high pitched noise coming out of the alternator, other than that it works fine, I never noticed it in my last thirdgen, and I used the same alternator?
It's not that loud.
Last edited by tompumped; Apr 24, 2007 at 07:13 PM.
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Re: Coi + wire has 14 volts at idle, why???
Ummm, your entire electrical system typically runs at about 14 volts while the alternator is turning. I have a feeling the MSD guys are right.
Last edited by pizza_guy; Apr 24, 2007 at 12:20 PM.
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Re: Coi + wire has 14 volts at idle, why???
[quote=tompumped;3316430]I recently installed an MSD 8920 and I powered it through the original coil positive wire. I'd like to know why the coil positive wire would have 14 volts running at idle. quote]
It takes 13.8 just to charge a car battery. 14 isn't out of line.
It takes 13.8 just to charge a car battery. 14 isn't out of line.
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Car: 88 firebird
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Axle/Gears: 9 bolt 3.91
Re: Coi + wire has 14 volts at idle, why???
I didn't think the voltage should be that high for some reason. thanks
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Re: Coi + wire has 14 volts at idle, why???
Everyone else is right, mines the same thing. If it bothers you that much you could always get a lower amperage alternator
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Re: Coi + wire has 14 volts at idle, why???
also, the high pitched whine is normal too. It is the internal regulator of the alternator. How loud it is varies from car to car, and for different alternators.
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From: NY
Car: 88 firebird
Engine: 355
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Axle/Gears: 9 bolt 3.91
Re: Coi + wire has 14 volts at idle, why???
Never said it bothered me, I just thought it would be lower at idle.
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