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Discussion Starter #1
Converting to an internally regulated alternator-going to use the 94 amp 12SI model.

Saw the diagram on here to connect the #1 and #4 wires together where they connect to the voltage regulator, then connect the "blue" wire to the V+ sense lead connection on the alt. Since I don't have an idiot light, do I just leave the other connection open?

I've heard you have to add a diode at the v-regulator splice, is that true?? If so, which diode (rating) and polarity??
 

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"Saw the diagram on here to connect the #1 and #4 wires together where they connect to the voltage regulator"

So far so good. The blue and brown wires tie together at the regulator. There is a kit available with a connector that has a shorting bar that you simply plug in. Soldering them together is cheaper.

"then connect the "blue" wire to the V+ sense lead connection on the alt."

Think you are misreading something. Blue is the field wire. The diagram shows the other lead tying to alternator B+ terminal.

"Since I don't have an idiot light, do I just leave the other connection open?"

Which other connection Sid? The blue wire? Hook it up as Wes shows. If you follow the brown (tied to blue) wire back through the bulkhead connector it still ties to the ignition switch.

"I've heard you have to add a diode at the v-regulator splice, is that true?? If so, which diode (rating) and polarity??"

Not true. You don't need it unless you have a MSD box. Did you follow that brown wire back to the ignition switch? See how it ties to the normally open side of the ignition switch? What happens when you turn off the key is that the alternator continues to output a voltage through the blue/brown wire. With a points ignition the ignition coil acts as a load and bleeds the pink wire thus shutting off the car. With the very low current the MSD takes, the blue/brown wire keeps feeding the pink ignition line and the car continues to run. The diode blocks voltage one way, from the alternator to the ignition switch to prevent this from occurring.
 

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Discussion Starter #3
Thanks for the quick response John!

I'll clarify:

12SI has 3 connections: 2 on little plug on top (think they're VSense and the idiot light connection), plus the B+ hi output feed to the electrical system.

My car's missing the original feed, had the old alternator's output wired directly to the battery. Now that I've done the reading between here and the Excellent site http://www.madelectrical.com , going to run an 8 gauge wire from alt. to a terminal I'm going to mount near the horn relay as a master tie point. That way the entire bus is running at 14.2 (brighter lights), the battery gets the benefit of a slight resistance in the wire from the tie point to the + terminal (slower charge rate=longer batt. life).

Dave just answered my question. Thanks to all!!!
 

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Discussion Starter #4
Now I just gotta figure out the right value of fusable links to add to the system. Assuming a 94A alternator, 8 gauge wiring?

I'm guessing I need one close the B+ output of the alternator, 1 close to the + side of the battery on the charging lead. Something I learned installing stereo stuff: always fuse nearest the sorce
 

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Originally posted by Sid Coleman:
Now I just gotta figure out the right value of fusable links to add to the system. Assuming a 94A alternator, 8 gauge wiring?
It's done by wire gage. Normally 2 sizes down from the wire used so on your 8 gage it would be a 12 gage fusible link. I don't know if they are avaialble in that gage over the counter. At one time I found a site where someone showed a way to make them. Maybe I still have that information at home and maybe not.
You understand that increasing the wire gage and fusible link has a disadvantage that people on other sites don't mention. That is, for the most part, it's going to take one large short to ever burn a 12 gage fusible link.
Give this a little thought and let me know what you think. How about leaving the existing circuit alone; Getting a positive cable with 2 pigtails on it; running the second pigtail to your extra add-on block; Jumping that block back to the alternator (if you want). Basically a parallel set of wires. (Fusible links added.) Meets what you want it to do without overfusing the circuit.
 

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Discussion Starter #7
Very good point John, thanks!!
 

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Originally posted by CHELKAMINO:
</font><blockquote>quote:</font><hr /> "I've heard you have to add a diode at the v-regulator splice, is that true?? If so, which diode (rating) and polarity??"

Not true. You don't need it unless you have a MSD box.
I am using an MSD box....what diode????
And where does it go!!!!!
Thanx
Brian
</font>[/QUOTE]Click on www.msdignition.com
Go to INSTRUCTION DOWNLOAD
Click on that
Click on MSD 6 SERIES
Download that file. The wiring instructions are on page 8.
 

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Did you get it figured out?

I'd put a fusible link sized for 10 gauge at the battery connection. Run the 8awg with the fusible link to the new rad support terminal block. Then, jumper a fusible link sized to protect 10 gauge to the horn relay to power the origional car components and charge the battery. Hook the high power accessories to the new terminal block. Take the voltage sensing terminal connection on the alternator out to the new terminal block to maintain full output voltage at that point. With this configuration, all of the origional wiring is protected plus you have a new terminal block for high power accessories (I bet it's an electric fan).

I would further recommend connecting the voltage sensing wire to the horn relay but only if the new accessories can't be damaged by voltage surges and problems that could happen if the new terminal to horn relay fusible link blows. Fans and pumps would be fairly immune to this happening but something like an MSD box probably isn't.

Originally posted by Sid Coleman:
the battery gets the benefit of a slight resistance in the wire from the tie point to the + terminal (slower charge rate=longer batt. life).
I've yet to figure out how < 5' of 10 gauge wire really helps to protect the battery by charging it slower. You can crank around 50A through a 5' piece of 10 gauge with only a 0.25 volt drop or 20A with a 0.09 volt drop. I'd really like to see MAD's laboratory testing data that proves this helps the battery.

Peter
 

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Have to say that some of the information from MAD is really excellent and well written. I have linked to their articles a few times. However, in some places I don't see how they came to a conclusion. Maybe I'll just read them a few more times.
 

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I'll agree John, they do have very good info on how the electrical system works on the car and the site is a very good reference. They also have some decent products available (although nothing exclusive to them). I believe there strength is in the explanations they provide with their products.

It's just that some of the explanation ends with a reason to use their upgrade or modification which is in essence the sales pitch part of the explanation.

I should add that a completely seperate reason for adding a Ford solenoid AT THE BATTERY would be to remove the power from the heavy starter wire running through the car which helps protect the car in case it ever shorts. The bad part is that you then have to run another smaller sized power feed wire which can introduce it's own problems with additional voltage drop.

Peter
 
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