the death of an alternator

Gotta love that wiring . . .
baltobernie
Patron 2020
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Your car is a: 1973 Spider [sold]
Location: Baltimore, MD

Re: the death of an alternator

Post by baltobernie »

Here is the "Theory of Operation" of the charging circuit of an internally-regulated alternator, from my Painless article. This may help you understand how the system works. The Fiat circuit is (naturally) more complicated, but the idea is the same. The element in the lamp provides a small amount of resistance which tells the alternator to charge, so to speak. If the exciter wire and output wire are presenting the same voltage, the alternator will run "wide open" all the time, 15-16+ volts.

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eugrides

Re: the death of an alternator

Post by eugrides »

my charging light lites very dim when headlights are on yet alternatot is putting out 14 volts whats up where headlight ground
eugrides

Re: the death of an alternator

Post by eugrides »

my charging light lites very dim when headlights are on yet alternatot is putting out 14 volts whats up where headlight ground
baltobernie
Patron 2020
Patron 2020
Posts: 3466
Joined: Sun Nov 25, 2007 6:00 pm
Your car is a: 1973 Spider [sold]
Location: Baltimore, MD

Re: the death of an alternator

Post by baltobernie »

If the lamp is lit, more current is going out of the battery than back into it. The brighter the lamp, the greater the imbalance. Drive your car to a big box auto parts store, and have them measure the output of the alternator while in the car.
eugrides

Re: the death of an alternator

Post by eugrides »

charging light is lit dim headlights on, blower on , alternator still putting out 14 volts of course car is running
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