New Alternator Wiring Upgrade Configuration

[svxfiles]

Originally Posted by svxcess

I am fairly certain that when I pulled the rubber sheathing/insulation off of the two white wires, one was intact and just needed to be cut and a ring terminal attached.

I am sure the other white wire had a factory splice of three wires into one,

That is correct.

[svxcess]

As an alternative to running the two white wires, currently attached to the battery, back to the alternator, can I do this?

Run both wires to one terminal of a maxi-fuse holder and the other terminal with a wire to the battery. If so, what would be the preferred size fuse? I am thinking 60A or maybe 80A. It should give me the same protection

Or would a Magnum fuse be better? These fuses come in 100A and 125A

I have found there are two opposing schools of thought on using fusible links:


PRO: Ford Motor Company Motorsports Division
The fusible link is a type of fuse usually molded into the cable linking the alternator to the battery. It should be rated about 150% of the rated alt output current, so that it will not blow if the alternator is supplying its rated power.

(My comment: If this is true, the fusible link would now have to be rated at 240A.)

The fusible link is incorporated to protect the system by blowing if the diode pack in the alternator fails. In this case the diodes have a high probability of failing to a short circuit, allowing enormous amounts of current to flow throught the wiring harness, and melting all circuits in close proximity greating a fire hazard.

The link blows and isolates the alternator from the balance of the wiring. The alternator would be destroyed electrically (but not mechanically) by the time the link blows.

Do not substitute a fuse or circuit breaker for the fusible link, as if it blows or is switched open while the alternator is operating, the sudden load loss will cause the alternator output voltage to soar to the point where it destroys the diode pack. This is the reason the fusible link is rated much higher than the alternator.

But supposedly the fusible links are slowly being replaced with Maxi Fuses




AGAINST: Ron Francis Wiring www.ronfrancis.com
Maxi-fuses have replaced fusible links for a reason! Fusible links first appeared in the late 60's as a solution for protecting some of the heavier wires in a vehicle that years earlier were not protected at all.

Fusible links have burned in half while doing their job, but these have caused fires, since they can have quite a flash when they burn through. This is reason enough why they have been replaced.

I have seen them catch fire while "protecting" a vehicle. Imagine what would happen if there was fresh paint or a shop rag nearby! As a manufacturer of one of the highest quality, state of the art custom automotive wiring harnesses, I have never used fusible links and I never will!

I tend to believe Ron Francis... any advice? Seems I have 4 options:

1. Leave it the way it is now with the fusible link bypassed.
2. Run the two white wires back to the alternator (and the original configuration) as discussed earlier in this thread.
3. Use the maxi fuse holder and a 60A or 80A maxi fuse close to the battery
4. Use a magnum fuse holder and a 100A or 125A magnum fuse close to the battery.

,

[Trevor]

Originally Posted by svxcess

As an alternative to running the two white wires, currently attached to the battery, back to the alternator, can I do this?

I note that only to information provided commercially as part of advertisement, has been referred to. Not a good idea.

** Do not substitute a fuse or circuit breaker for the fusible link, as if it blows or is switched open while the alternator is operating, the sudden load loss will cause the alternator output voltage to soar to the point where it destroys the diode pack. This is the reason the fusible link is rated much higher than the alternator.

My e-mail to john, dated, 9/03/09.

The basic requirement for charging is to have a heavy fused charging circuit, alternator to battery and a separate light (little current is involved) direct voltage sensing circuit, battery to alternator regulator (alternator plug terminal 2).

My car has only a single wire and connection at the main charging terminal post, where as you advise that your car has two. You have drawn the original configuration with one wire direct to the battery and this does not appear correct as it would be unprotected. Could this have been added by a previous owner. There should also be a wire direct from the battery positive to the fuse box. Alternatively is the US wiring arranged differently?

Unfortunately there was no response to this e-mail.

My post #43. Voltage sensing is combined with other circuits and the only protection for same is the fuse link. Surely a separate sensing conductor should be provided, protected by a properly rated fuse and supplied from the battery side of the positive bus bar. This could well form part of any upgrade.

My post #56. The rating of the fusible link was sorted out some time ago, but I can’t recall the exact figure. If I remember right, the figure 1.5 indicates a wire gauge/thickness. Alternative sources of supply were being sort at the time. Do a search, it’s all there somewhere.

My post #58.

It can only be assumed that the diagram is in error and what I have described is the actual original set up. My car is a JDM so that I can not use it as a reliable match with yours, therefore I must ask you to confirm all is as I say.

At that point I can advise regarding your very best arrangement. Meantime all circuits are connected and the problem is confined to fusing and is purely a safety issue.

The original arrangement has not been confirmed and this is certainly information which valuable and should be recorded within the network.


I now detail my recommendation for best possible arrangement as a final offering within a thread which has become a frustrating waste of time:-

Fit a heavier main charging circuit conductor if such is desired, incorporating a suitable inline fuse close to any direct connection to the battery.

Ensure that a separate voltage sensing conductor (only a fairly light gauge is required) is installed from alternator connection 2, direct to the battery or battery circuit. This circuit should be fused battery end, at 10 amps. The result is a standard fuse link, over rated on purpose. This circuit, which I have previously mentioned, will cover the point outlined above. (See **) Provided the voltage sensing circuit is intact, there will be no run away of the alternator.

It will be best if the battery connection is made at the fuse box and to the incorporated distribution bus bar connection point. There mast be an existing wire so connected, which can be used, so that accessing the fuse box is not required. This will achieve a tidy workmanlike job, without multiple connections to the battery terminal.

A separate conductor is required between the protected end of the fusible link, i.e. via fuse box terminal 1, bridged to terminal 2. and SBF holder terminal 2. The facility for these connections will surely exist, but will require sorting and possible amendment.

I believe that the SVX fusible link, as factory mounted and protected by a heat resistant sleeve, does not constitute a fire risk. What is more, in practice members have recorded a link opening without problems.

Unfortunately I have not been in a position to outline in detail all required alterations, as I have not had exact information covering the factory installation.

[svxcess]

This has all gotten too complex and confusing for me. I am just going to take those two white wires, splice them into one larger 8 gauge wire, and take them back to their original connection at the alternator. Factory fusing circuit and protection will again be maintained as designed.

Not my first choice, but definitely the easiest.

My original question in the above post was a simple one. If I were to leave the two white wires attached at the battery and wanted to protect that circuit with a fuse, which one should I go with? Either the Maxi Fuse or the Magnum Fuse, and what amperage?

.

[Trevor]

Originally Posted by svxcess

This has all gotten too complex and confusing for me. I am just going to take those two white wires, splice them into one larger 8 gauge wire, and take them back to their original connection at the alternator. Factory fusing circuit and protection will again be maintained as designed.

Not my first choice, but definitely the easiest.

My original question in the above post was a simple one. If I were to leave the two white wires attached at the battery and wanted to protect that circuit with a fuse, which one should I go with? Either the Maxi Fuse or the Magnum Fuse, and what amperage?

.

Dear John,

When correctly connected, the secondary alternator control wiring does not require a maxi or magnum fuse holder.

I gather you are talking about wires which should run to the alternator plug/socket connection numbered 2. I have no information as to how these wires are connected to the alternator in your revised arrangement. Without this information I can not PROPERLY answer your questions.

It was because of the lack of clarity, that I decided to spend a great deal of time, detailing the most desirable set up. Reasoning that with this information on hand, you could decide for yourself your best course of action.

Going through all your posts I now find advice as follows -

#1 states - ” Looking inside the original black plastic wiring channel that runs along the rear of the A/C compressor and alternator you will find two white wires that attach to the alternator CHARGING POST.”

If your description is correct, the wiring is incorrect.

#49 - Indicates the main output terminal post, by means of a photo and the text states -

“The other thing that could be done is to take the two white wires that are now connected at the battery and splice them into one 8 gauge wire. Run this wire back, under the manifold, to its original connection at the alternator. Connect it from the opposite side of the alternator post. It would still be protected with sleeving as the others.”

Again the alternator post is clearly indicated in the photo, rather than the plug socket.

#34 -”I am attaching the complete Power supply routing diagram from the FSM. The two wires circled in green are the ones I removed. Remember that one of those smaller 10ga wires that was replaced was the original charging wire back to the battery. I just replaced it with one for better current flow and less resistance = less heat = more current/ voltage.”

The diagram indicates by means of a marked wiring, two wires attached to the main charging binding post.-


#49 Once again the the main alternator terminal is described within the text and shown in a photo. You again specify the post as being the original connection.

#57 Includes the text -

“I would take the two white alternator wires (which were shortened and attached directly to the battery) and splice them into one larger 8 gauge wire. I would them run them back to the alternator under the manifold and reconnect them to their original connection point on the alternator from the opposite side.”

#58 - (My post) reads -

Good one John.

"Our problem is that the wiring diagram, as has now been kindly published within the thread, does not appear to coincide with the actual car wiring, particularly in regard to junction points.

It can only be assumed that the diagram is in error and what I have described is the actual original set up. My car is a JDM so that I can not use it as a reliable match with yours, THEREFORE I MUST ASK YOU TO CONFIRM ALL IS AS I SAY.

At that point I can advise regarding your very best arrangement. Meantime all circuits are connected and the problem is confined to fusing and is purely a safety issue.

After becoming involved in this lengthy and confusing topic, I have second thoughts regarding returning to the site!"

#60 - You advise, without specifying the exact connection points on the alternator, which you would use.-

“I would take the two white alternator wires (which were disconnected from the alternator, shortened and attached directly to the battery) and splice them into one larger 8 gauge wire. I would them run them back to the alternator under the manifold and reconnect them to their original connection point on the alternator from the opposite side.
The electrical circuit would be exactly the same as the original circuit as designed, but with the alternator wiring upgrade and inline fuse.”

#62 - “As an alternative to running the two white wires, currently attached to the battery, back to the alternator, can I do this?
Run both wires to one terminal of a maxi-fuse holder and the other terminal with a wire to the battery. If so, what would be the preferred size fuse? I am thinking 60A or maybe 80A. It should give me the same protection”

#64 - “This has all gotten too complex and confusing for me. I am just going to take those two white wires, splice them into one larger 8 gauge wire, and take them back to their original connection at the alternator. Factory fusing circuit and protection will again be maintained as designed. Not my first choice, but definitely the easiest.

My original question in the above post was a simple one. If I were to leave the two white wires attached at the battery and wanted to protect that circuit with a fuse, which one should I go with? Either the Maxi Fuse or the Magnum Fuse, and what amperage?”

John, if you had advised me as to where the two white wires have been connected in your set up, I could have answered your questions. Meantime I can only say that standard size fuse holders are required for the secondary circuits, not Maxi or Magnum fuses.

At the moment I have some concern as to what you may have wound up with. In particular regarding the alternator secondary connections which you have never confirmed. The car will run and the alternator will charge, with everything connected to battery positive, by any route, in any arrangement. But, there could be no protection for the circuits. Bad, bad news for sure.

You complain, “This has all gotten too complex and confusing for me.”

Please reserve a thought for me at this end!!!

There is sufficient information detailed in this thread, for you to sort out in your own mind what is best for you. I have given you my opinion on what is preferred. I suggest you take a pen and paper, or better still use copy and paste, to extract exact relevant data from this thread, leaving out any superfluous chatter. With it all listed together, it should not be difficult to understand and make your own decision, and you will become fully aware of what you are about. Note that I have covered in detail, the fuse rating required for sensing circuit.

Give it a go. Trevor.

[Francis]

confusing for me too....i cant wait to see how it ends , i'm thinking of changing my alternator too. i am waiting to see the best solution...you guys make great work not burning da house

[LetItSnow]

I'm looking forward to the answer to having two white wires in the first place. Just because it can be first and easiest understood as a pair of wires splitting the current between them doesn't mean that it is absolutely the same with a single wire in their place, solely for the fact that it's unlikely the effort would have been gone through to place two wires where one would have done the trick.

A best guess would say that there was an application that demanded a pair of wires rather than one, kind of like that appendix that most of us carry around fruitlessly (mine was yanked when I was 8; I missed Halloween.)

I've always been a firm believer that if something seemingly senseless or wrong exists, no matter how utterly stupid or illogical it may seem, someone somewhere must have thought it was a good idea for some reason. I'd like to know the reason for using two white wires.

[Trevor]

Originally Posted by LetItSnow

I'm looking forward to the answer to having two white wires in the first place.

I've always been a firm believer that if something seemingly senseless or wrong exists, no matter how utterly stupid or illogical it may seem, someone somewhere must have thought it was a good idea for some reason. I'd like to know the reason for using two white wires.

On the basis of logical detective work from afar (Not the logic of the best electrical arrangement), I believe that the thin white wire runs to the SBF holder, Sub Board fuse holder??????

[svxcess]

Part of the confusion is that both wires that were commected to the alternator are IDENTICAL IN COLOR AND GAUGE. This makes them hard to determine which one goes where. There is no one wire that is thinner than the other.


On the stock 2-wire factory alternator connector (which plugs into the side of the alternator), the bottom wire is heavier than the top wire. However when you get a replacement plug from any alternator shop, both wires are now the same gauge.


.

[svxcess]

Originally Posted by LetItSnow

I've always been a firm believer that if something seemingly senseless or wrong exists, no matter how utterly stupid or illogical it may seem, someone somewhere must have thought it was a good idea for some reason. I'd like to know the reason for using two white wires.

Originally Posted by Trevor

Only a single quite heavy wire on the alternator main charging terminal, on my 92 JDM SVX.

Trevor seems to be the only one who has only one white wire. How heavy would you guess it to be, heavier than 10 gauge?

The cars with two white wires have wires that are 10 gauge each. Could they be substituting a larger gauge wire for the two smaller ones?

Originally Posted by LetItSnow

A best guess would say that there was an application that demanded a pair of wires rather than one.

I wonder what applications our cars, (and even Harvey's) have that requires the need for 2 wires that is missing on Trevor's car. Even if it was a market difference, that doesn't explain the facy that Harvey's 95 JDM in Australia has 2 wires and Trevor's 92 JDM in New Zealand has only one.





.

[oab_au]

My car is an Australian Delivered Model.
A lot like the UK model.

Harvey.

[svxcess]

Originally Posted by Trevor

On the basis of logical detective work from afar (Not the logic of the best electrical arrangement), I believe that the thin white wire runs to the SBF holder, Sub Board fuse holder??????

According to the manual, SBF stands for slow-blow fuse.

SBF: Slow Blow Fuse
These act as a fusible link for the main groups of circuits and as such cover more circuits than just engine management.

These fuses have a time-lag characteristic to withstand heavy surges, yet they will blow quickly on high overloads or short circuits. These are designed for circuits having high inductive or capacity surges, or heavy starting currents.

,

[Trevor]

Originally Posted by svxcess

According to the manual, SBF stands for slow-blow fuse.

SBF: Slow Blow Fuse
These act as a fusible link for the main groups of circuits and as such cover more circuits than just engine management.

These fuses have a time-lag characteristic to withstand heavy surges, yet they will blow quickly on high overloads or short circuits. These are designed for circuits having high inductive or capacity surges, or heavy starting currents.

,

I am fully aware of all types of fuse links and there characteristics, my company having distributed a line of HRC fuses.

If that is what the draughtsman is illustrating, it makes me even more sure that his drawing is crap, as he shows it as an individual external component, linked to an external common conductor. The single line to the alternator, which has been shown in fact to illustrate more than one conductor, has caused much head ache. His is not a wiring diagram, and it is most certainly not a schematic.

Unfortunately common in the automotive world and which makes us industrial electrical engineers --- . It is one hell of a mess. One such mess would have had me in court.
__________________
Trevor, New Zealand.

[VICSVX]

OK, this has gotten WAY to confusing for me....is there anyone in the tucson area that has done it and woundn't mind doing for me lol

im not good at all this elecrical stuffand i just got a 160a alternator...

[svxcess]

.

UPDATE


Maniac Electric Motors is now offering a lifetime warranty on all of their high-output alternators for an additional $98.00.

The original warranty on these units is one year.

More details on their site HERE


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