ONE WIRE ALTERNATOR AND JUNCTION BLOCK??

[Matt69olds]

One wire alternators won’t charge at idle until the throttle is opened, after that it will charge. They also have no warning light, I guess that’s not a big deal as long as you have a voltmeter and actually pay attention to it. I have never understood the fear people have of basic electrical work, one wire alternators have their place, but daily driver vehicles are not one of them. Find a upgraded OEM part, that way if your 10 miles northeast of nowhere will charging system issues you can get a replacement part.

 

[trukman1]

It one reason why imo 1-wire alts have NO place on a regularly driven vehicle. It puts out too much amperage when it isnt even needed. 3-wire setup w/remote voltage sensing is always the better route.

THIS!!!

 

[Frankenchevy]

Most any new alternator is internally regulated.

I just spoke with a friend that’s an automotive engineer. He said he’s tested this several times and told me to try it for myself. Anyone can test this themselves by putting an amp clamp over their charge wire.

His findings were that a high output alternator will deliver an average of 50 amps to a completely discharged 800cca battery. It is only delivering that momentarily. It will continue to deliver less and less when approaching a fully charged battery all the way down to .3-.4 amps or less.

He also mentioned that most charging wires are 10 gauge on passenger cars and light trucks.

Also keep in mind, amp to wire gauge charts are mostly assuming that the conductor will be run through a conduit or raceway. Wires in the open can carry many more amps safely.

A perfect example is the gauge of wire coming in from the street transformer to your house’s weather head. It is significantly smaller than what you local jurisdiction will require in the mast to your meter socket.

I’m all for the overkill train of thought for wiring in most applications though.

 

[DoubleDingo]

Just quoting this because I think it needs more emphasis.

How the heck is a 1-wire alternator an upgrade? Far as I know, the purpose of a 1-wire alternator is just for guys building hot rods that don't feel like running the proper amount of wires.

Hey I resemble that remark! But really, I was ignorant when I rewired my truck. It had the 3-wire with the external voltage regulator, and a guy at a speed shop showed me the 1-wire alternator and I thought it was way cooler than the 3-wire. And since the Painless Kit had provisions for both, I bought the 1-wire and ran with it. But I have thought about switching it back to 3-wire with the voltage regulator so it looks more period correct.

I'm liking this thread, some good info in here.

 

[Frankenchevy]

I’m actually really interested in this test. Once my truck is buttoned up and running well, I’ll try running my 175 amp alternator to a dead battery to see the draw.

 

[80sHottrodder]

My original intent was to wire it up how G.M. had it. I tried both ways and the truck actually holds a steady voltage with just one wire. When I first start the truck it sits at a steady 14 volts now. The instructions said it could be hooked up either way but the truck was getting less voltage hooked up with three wires. I dont know why that would be though.

 

[Frankenchevy]

My original intent was to wire it up how G.M. had it. I tried both ways and the truck actually holds a steady voltage with just one wire. When I first start the truck it sits at a steady 14 volts now. The instructions said it could be hooked up either way but the truck was getting less voltage hooked up with three wires. I dont know why that would be though.

Was the ‘s’ wire ran to the main junction on your firewall?

 

[80sHottrodder]

Was the ‘s’ wire ran to the main junction on your firewall?

Yes.

 

[80sHottrodder]

Unless you mean the start wire on the solenoid. Thats ran to a switched ignition on a different circut.