The Ford Barn

2speed · 06-23-2025, 09:39 PM

I bought a 6v positive ground alternator because I felt that was easiest, and it worked great for about 600 miles. Today was HOT, and I noticed that it was pegging the ammeter. I turned on the headlights and brought it down to 20 or so amps to make it home without frying something. I believe it used to charge at like 7.2V or there abouts, now it's just making 6.88V and is according to the ammeter putting out like 15 at idle, and pegging it at anything above idle.

How reliable are these? Anyone have experience? Did I just get a bad one? Are 6 volt negative ground more reliable? Should I bite the bullet and just go to 12 Volts?

Are the starter Bendixes that fragile at 12 Volts?

When changing the coil do you opt for external resistor or internal resistor?

I'm not going back to the generator, I like having my lights not dim at stoplights and not having to worrying about cooking my battery.

06-23-2025, 09:39 PM	#1
2speed Senior Member Join Date: Apr 2022 Posts: 105	Alternators I bought a 6v positive ground alternator because I felt that was easiest, and it worked great for about 600 miles. Today was HOT, and I noticed that it was pegging the ammeter. I turned on the headlights and brought it down to 20 or so amps to make it home without frying something. I believe it used to charge at like 7.2V or there abouts, now it's just making 6.88V and is according to the ammeter putting out like 15 at idle, and pegging it at anything above idle. How reliable are these? Anyone have experience? Did I just get a bad one? Are 6 volt negative ground more reliable? Should I bite the bullet and just go to 12 Volts? Are the starter Bendixes that fragile at 12 Volts? When changing the coil do you opt for external resistor or internal resistor? I'm not going back to the generator, I like having my lights not dim at stoplights and not having to worrying about cooking my battery.