How do I change over from an external regulator to an internally regulated alternator on a 1970 vintage Chevy 350? Looks like 2 wires going to regulator and the large charging wire to the alternator. Any help appreciated.

go here http://67-72chevytrucks.com/board/Ultimate.cgi look back about 5-7 day's in the 68-72 forum. they just covered this. You have to jumper the plug that goes to the regulator. It's pretty easy to do. They have a picture of it. I for the life of me can't remember the title of the post. I think it was someing like "converting to single wire alternator".

Here's the thread:

http://67-72chevytrucks.com/board/ubbhtml/Forum1/HTML/013957.html

Pete

*FJ4ZROX* Asked,
*How do I change over from an external regulator to an internally regulated alternator on a 1970 vintage Chevy 350? Looks like 2 wires going to regulator and the large charging wire to the alternator. Any help appreciated.*

You just got some bad information....
AND...
You are confused...

The #1 terminal of a Delco SI series alternator is the exciter.
It is powered by a switched source. You can use the ignition switch or a toggle switch.
You can also use a resistor in place of the light, but a light is preferable because of it's early warning of charging failure.
Power should come through the key switch, It should be run through an 'Idiot' light, and to the #1 terminal.
You must use a light fixture that controls both sides of the circuit, It can NOT be a grounded fixture.
You may use light gauge wire for this circuit, like as small as 18 GA.

SIDE BAR...
If you experience engine run on after you turn the ignition key off, you may have to install a 'Diode' in the wire next to the plug for the alternator. The Diode uses a symbol to show current flow, an arrow and a straight line, wiring will look like this, Wire----->l-----Alternator Plug. This Diode is under $2 at Radio Shack.

The #2 wire is the Field supply to the alternator.
This is the circuit the regulator uses to decide if more or less supply is needed.
This connection should be someplace at the end of the power supply trail if possible, like after the fuse box somewhere.
I use the horn relay in most cases.
This will keep nominal voltage up high enough you get 13 or 14 volts at the end of the wiring harness.
If you connect this wire to the battery, you will keep the battery at 13 or 14 volts, but the rest of your power system will suffer, especially if you have old, corroded connections, and high drain devices hooked up in the vehicle.

The third connection is the "BATT" terminal on the back of the alternator.
This terminal should go through a fusible link (Fuse Wire) and connect to the battery cable side of the starter solenoid.
DO NOT connect directly to the battery!
If the fusible link burns and it's hooked directly to the battery, you may blow the battery up.
Use one or two sizes smaller fuse link than you are wire from the alternator to the battery cable side of the starter solenoid. You should probably use 8 GA. wire from the Alternator to the fuse link, and use a 10 or 12 GA. fuse link.

The fourth connection is the Ground directly from the alternator to the battery or primary ground stud.
If you use 8 GA. wire from the alternator, use an 8 GA. ground from the back of the alternator to the primary ground.
The second largest circuit on your vehicle (behind the starter circuit) and the most used circuit is the charging system circuit.
You can not complete the circuit with out a proper ground, so don't omit this wire.
This does not take the place of the engine ground or the starter ground wire, this is an independent ground, and must attach to the alternator case.

See Attachment.

<IMG SRC="http://bbs.off-road.com/wwwthreads_uploads/9-598851-DelcoSIWiring.gif"

The #2 wire is the Field supply to the alternator.
This is the circuit the regulator uses to decide if more or less supply is needed.
This connection should be someplace at the end of the power supply trail if possible, like after the fuse box somewhere.
I use the horn relay in most cases.
This will keep nominal voltage up high enough you get 13 or 14 volts at the end of the wiring harness.
If you connect this wire to the battery, you will keep the battery at 13 or 14 volts, but the rest of your power system will suffer, especially if you have old, corroded connections, and high drain devices hooked up in the vehicle.

This is interesting/good to know, as I believe mine is basically tied to the bat terminal on the alt. Perhaps I will look into it for more juice during high-drain activites.

The third connection is the "BATT" terminal on the back of the alternator.
This terminal should go through a fusible link (Fuse Wire) and connect to the battery cable side of the starter solenoid.
DO NOT connect directly to the battery!
If the fusible link burns and it's hooked directly to the battery, you may blow the battery up.
Use one or two sizes smaller fuse link than you are wire from the alternator to the battery cable side of the starter solenoid. You should probably use 8 GA. wire from the Alternator to the fuse link, and use a 10 or 12 GA. fuse link.


Why would the battery blow up if the batt terminal is hooked directly to the battery (through a fusible link), if the fuse-part is kept near the alt?

Pete

Originally posted by pcorssmit
[B]

Why would the battery blow up if the batt terminal is hooked directly to the battery (through a fusible link), if the fuse-part is kept near the alt?

Pete

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....another comedian....
Or maybe one of those armchair experts...

You don't put the fuse link at the beginning of the supply circuit (IE: At the alternator).
The fusible link is a restriction, and you never put a restriction at the beginning of a circuit.
I also don't want that fusible link up around my intake manifold, just incase there is any leaking gas fumes or anything else flammable....

That only leaves the "To the battery" end...
And, sense you can't go directly to the battery because you don't want to put a burning fusible link next to a battery that was just charging and emitting large levels of Hydrogen Sulfide gas (can you say 'The Hindenberg'), you go to the next best (and safest place) the battery cable side of the starter solenoid.

WHY? WHY? WHY? I can already hear it coming... (I've got a 2 year old nephew that sounds just like this...)

The largest circuit in the vehicle is the starter circuit. In voltage, amperage, and/or watts.
The second largest circuit in the vehicle is the charging system. It's also the most used.
IF you go to the positive battery cable side of the starter solenoid, it will be the safest place to take the voltage and amperage to the battery, and not set anything on fire/ blow anything up...

Or how about this one...
A guy bright enough to know how everything works, bright enough to tell YOU where everything should go, and bright enough to make the graphic even you can understand TOLD YOU TO!

PAY ATTENTION AND FOLLOW INSTRUCTIONS, and you might not have to walk home...

Originally posted by TeamRush


--------------------

....another comedian....
Or maybe one of those armchair experts...

You don't put the fuse link at the beginning of the supply circuit (IE: At the alternator).
The fusible link is a restriction, and you never put a restriction at the beginning of a circuit.
I also don't want that fusible link up around my intake manifold, just incase there is any leaking gas fumes or anything else flammable....

That only leaves the "To the battery" end...
And, sense you can't go directly to the battery because you don't want to put a burning fusible link next to a battery that was just charging and emitting large levels of Hydrogen Sulfide gas (can you say 'The Hindenberg'), you go to the next best (and safest place) the battery cable side of the starter solenoid.


I think I understand now. By adding 8' of extra wire to the circuit's path, my charging system will operate at a higher effieciency. :D

Originally posted by TeamRush

The largest circuit in the vehicle is ...

Newbie's attitude! :flipoff2: :flipoff2:


Pete

Nope, I was wrong, this clown isn't trying to be a comedian, he's just too stupid to understand directions....
Doesn't have enough I.Q. points to figure out safety issues...
And doesn't have a clue on how to build an electrical circuit...

He just doesn't have any thing better to do that cause problems here...
What a pathetic looser.

Not only is he trying to give me a hard time (which is going to get him b*tch slapped), but he is wasting server space and bandwidth here...
-----------

As to the 'Newbe' thing....
If Obnoxo-The-Clown had been here a year or two ago, he might remember my posts when this place was still a graveyard....
That's the problem when something gets popular, you get posers trying to act like real people...

Too bad the people that were here in the beginning aren't here now, there were some real bright guys around in the beginning...
Sniveling, childish clowns like this one is probably the reason why.

Maybe they will get a 4X4 poser day care center for guys like this one...

BTW, this guy gives me crap, but this is what he drives...

<IMG src="http://www.streetjeeps.com/photos/Sweet_Jeeps/640/streetjeep3.jpg" border="0" alt="">

I'm sure he looks like an Oompa-Loompa too...

Now, we'll just let Obnoxo-The-Clown get the last word in, so he'll go lay down somewhere...

Hmmm, looking at the factory wiring diagram for my truck, it seems that the wire goes directly from the batt terminal on the alternator to the battery. No fusible link. Guess that explains all the TBI Chevys I've seen burning to the ground on the side of the road lately. Geez, theres hardly none left...:eek:

As for the pic, anyone who's been around here more than a week knows I traded in those gay stock rims on tripla go dubs ages ago...:flipoff2:

Pete

Will someone explain to this idiot that all new vehicles (1965 & Newer) have fusible links...

I need to remember what my grandpa used to say, "When a fool and a wise man argue, on lookers can't tell which is the fool..."...
Time for me to shut up now...
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What a goof...
I wonder how many times we are going to have to flush to get him to go away?....

I didn't say there are no fusible links. I said there is no fusible link in the connection from the batt. terminal to the battery. I don't have a scanner, or I would post a copy of this for you (1988 Light Duty Truck Wiring Diagram Booklet, GM, #ST-350-88, Section D-Page 2, Power Distribution). The batt terminal on the alternator is connected (without fusible links) to the field supply terminal and the battery. There is (obviously) a wire from the battery to the starter solenoid. The power supply to the rest of the vehicle is connected at the starter solenoid. There are two wires, both with fusible links. One goes through the bulk head connector and supplies power to the headlight switch and the horn/dim, t/l ctsy, and ecm 2 fuses. The other goes to the junction block (mounted on the firewall), then through the bulkhead connector and supplies power to the remaining circuits.

Pete