FRESH START: Alternator Wiring Upgrade Configuration

[svxcess]

Originally Posted by LetItSnow

One more and I'm out of this one for good:

If you protect the car's circuitry from the alternator with a 140 or 150A fuse, fusible link, or breaker, if your alternator has a problem, I'm prone to believe that it won't be your only problem.

If you don't have hardware demanding more amps, don't jack the protection; it doesn't make any sense.

You're probably right, Rob. I have been running the 80 inline fuse for over a year now without incident. Since it seems my electrical demands have never exceed this, I may just leave it there.

I never let my battery run down and use the Battery Tender for periods of extended storage. I never use my car to jump-start another vehicle; I use a portable battery pack for that. So there is not too much to put excessive demands on the electrical system.

Plus I am confident that this new alternator is built to a much higher level of reliability than our stock ones. It was Harvey's concern that I protect the alternator charging path from the rest of the circuitry at the 150A level.


Saves me a lot of work before Reading.... better used for other things like...


like.... uh....

Oh, yeah...

[Blacky]

I used a 60A inline fuse for my alternator mod because it was all that was easily available. It's been fine so far.

[oab_au]

I suggested the 150 amp fuse to cover all cases.

There are conditions that the alternator can exceed the normal output.

If the battery is very low in charge, when the engine starts, the charge rate to the battery could exceed 80 amps.

If someone (not John) had to jump start another car with a flat battery, the charge rate could exceed a 80 amp fuse.

Harvey.

[svxcess]

The whole thing is now finished and I am happy with it.

Thanks to everyone who took the time to adress their concerns. Especially I want to thank Trevor and Harvey for their tireless guidance. I had lots of options such as High-amp circuit brealers, MAXI fuses, etc that I needed to research and explore.

Thanks also to LetItSnow and SVXRide for some additional input and not letting me go too crazy with the protective circuits. With all that being said, here is the final configuration.

4 gauge power wire from the alternator to the battery with a 150A in-line MegaFuse as close to the battery terminal as possible. New 4 gauge ground cables to frame ground and engine

Alternator plug wires have been lengthened and rerouted underneath the intake manifold and reconnected as originally designed.


The two white wires that were originally attached to the alternator, that I shortened and attached directly to the battery, have been disconnected.

Once disconnected, I trimmed off the ring terminals, stripped the two wires and connected then together using solder and a crimped connector, followed by shrinkwrap. Safely tucked out of the way.

Thanks to Harvey for looking "outside the box" and discovering that by simply removing those 2 white wires from the battery and connecting them together, the safeguards of the original circuitry have been restored. I also like that my alternator charging path is now independent of the other circuits.


If you haven't seen it, here is Harvey's solution:


Remove the two white wires from the alternator output post, shorten them back, join them together. Don"t connect them to anything as they are already connected to the battery through the fusible link.

The Alternator is connected through your new wire and fuse to the battery.

It would look like this:

The ignition wiring that was connected to the alternator, now is connected through the standard fusible link, to the battery. This isolates the alternator output from the rest of the system wiring, so in the event that the regulator loses control of the alternator voltage, it won't harm anything from the high voltage.



I was hesitant to start it up. I turned the key and it immediately came to life. No warning lights, fireworks, strange burning smells... nothing out of the ordinary. Cold startup voltage was 14.4V which goes down to about 13.8V when at operating temperature. I will post final photos very soon.

It is now very secure, clean and uncluttered, and as safe as the original circuitry.

Thanks again to everyone.


.

[immortal_suby]

I'm electrically retarded. But this thread did convince me to remove my alternator wiring upgrade yesterday.
Maybe after a while I'll copy you, John. Sounds like you arrived at a good setup.

[svxcess]

Originally Posted by immortal_suby

I'm electrically retarded. But this thread did convince me to remove my alternator wiring upgrade yesterday.
Maybe after a while I'll copy you, John. Sounds like you arrived at a good setup.

There was nothing whatsoever with the original alternator wiring upgrade. All that was needed was an inline fuse in the 4 gauge alternator close to the battery. Adding wires was fine. You could have kept it without any problems.


The issues came when I was removing wires to make a different circuit, thereby bypassing a fusible link.


.

[Trevor]

[QUOTE=svxcess;595531]The whole thing is now finished and I am happy with it.


4 gauge power wire from the alternator to the battery with a 70A AGU inline fuse close to the battery terminal. New 4 gauge ground cables to frame ground and engine. (OK)

Alternator plug wires have been lengthened and rerouted underneath the intake manifold and reconnected as originally designed. (OK)


The two white wires that were originally attached to the alternator, that I shortened and attached directly to the battery have been disconnected. (At the battery end???)

Once disconnected, I trimmed off the ring terminals, stripped the two wires and connected then together using solder and a crimped connector, followed by shrinkwrap. Safely tucked out of the way.(At the battery end???)

The instructions:-
"Remove the two white wires from the alternator output post, shorten them back, join them together. Don"t connect them to anything as they are already connected to the battery through the fusible link. (This has not been confirmed.)

The Ignition wiring that was connected to the alternator, now is connected through the standard fusible link, to the battery."

N.B. The ignition an all distribution circuits were always connected to, and protected by the fuse link, from what we can ascertain. The logical conclusion is that the light white wire was originally connected to the SBF holder terminal 2 and the main alternator terminal. Leaving the two wires in place and connecting the ALTERNATOR ends together would retain this circuit. But a long loop may be included.

Connecting them together only, at the opposite (battery/fusible link) end, may not complete the SBF circuit, unless there is an existing separate loop wire to the SBF.

Without definite confirmation regarding the original connection of the two white wires, at the ends, not connected to the alternator charging terminal, nothing is certain, as the wiring diagram is apparently not accurate.

[Francis]

Alll this for 2 wires that are together! This is great seeing how it developed and how you found a good conclusion.
.

[svxcess]

[QUOTE=Trevor;595589]

Originally Posted by svxcess

The whole thing is now finished and I am happy with it.


4 gauge power wire from the alternator to the battery with a 70A AGU inline fuse close to the battery terminal. New 4 gauge ground cables to frame ground and engine. (OK)

Alternator plug wires have been lengthened and rerouted underneath the intake manifold and reconnected as originally designed. (OK)


The two white wires that were originally attached to the alternator, that I shortened and attached directly to the battery have been disconnected from the battery.

Once I disconnected those wires from the battery, I removed the ring terminals, stripped the two wires and spliced them together using solder and a crimped connector, followed by shrinkwrap. Safely tucked out of the way.

The instructions:-

"Remove the two white wires from the alternator output post, shorten them back, join them together. Don't connect them to anything as they are already connected to the battery through the fusible link. (This has not been confirmed.)

The Ignition wiring that was connected to the alternator, now is connected through the standard fusible link, to the battery."

N.B. The ignition an all distribution circuits were always connected to, and protected by the fuse link, from what we can ascertain. The logical conclusion is that the light white wire was originally connected to the SBF holder terminal 2 and the main alternator terminal. Leaving the two wires in place and connecting the ALTERNATOR ends together would retain this circuit. But a long loop may be included.

Connecting them together only, at the opposite (battery/fusible link) end, may not complete the SBF circuit, unless there is an existing separate loop wire to the SBF.

Without definite confirmation regarding the original connection of the two white wires, at the ends, not connected to the alternator charging terminal, nothing is certain, as the wiring diagram is apparently not accurate.

...............

[svxcess]

Originally Posted by Trevor

Leaving the two wires in place and connecting the ALTERNATOR ends together would retain this circuit. But a long loop may be included.

Trevor,

Is this what I should have done?

Peresently I have only a single 4 gauge alternator charging wire, with an inline fuse at the battery end, attached to the alternator post. This is fine.

The two white wires, that were removed from the alternator, have been shortened and are presently spliced together and protected with shrink wrap. Thet are not attached to anything but each other.

Should I take those two white wires that are now spliced to each other, and splice a larger, single, 8 gauge wire to them. Run that single wire back to the alternator post and connect it there?


.

[Trevor]

Originally Posted by svxcess

Trevor,

Is this what I should have done?

Peresently I have only a single 4 gauge alternator charging wire, with an inline fuse at the battery end, attached to the alternator post. This is fine.

The two white wires, that were removed from the alternator, have been shortened and are presently spliced together and protected with shrink wrap. Thet are not attached to anything but each other.

Should I take those two white wires that are now spliced to each other, and splice a larger, single, 8 gauge wire to them. Run that single wire back to the alternator post and connect it there?


.

John,

The two white wires should be reconnected as they were when the car was built, if you wish to adhere to the drawing posted. I do not know where they were connected. I do not know which ends, fusible link/battery end or alternator end, you have now joined together. (The two white wires, apparently are now completely out of circuit.) In any event I do not agree with the arrangement as has been illustrated, for good reason.

I have made it clear that the connection to the SBF, MAY be involved and you may now have this disconnected, due to the white wires being out of circuit. I do not know for certain, as the manual diagram is up the booha, dodgy, crook and bugger all good. Refer Bill’s confirming post #34. This thread is starting to brass me off.

I have twice advised the correct way to properly improve the existing system, refer my post #22. For the third time this data is repeated, with some additions so as to make the text even more clear, but with no technical alteration:-

I now detail my recommendation for the BEST POSSIBLE arrangement, as a final offering, (Big joke that turned out to be.) within a thread which has become a frustrating waste of time:-

Fit a heavier main charging circuit conductor as a replacement for the existing white wires from the main alternator terminal as now exist, incorporating a suitable inline fuse close to a direct connection to the battery. A connection, battery to fuse box, must remain intact.

Ensure that a separate voltage sensing conductor (only a fairly light gauge is required) is installed from alternator plug/socket connection 2, direct to the battery or direct battery circuit which does not include the fusible link. This circuit should be fused close to the battery end, at 10 amps, i.e. over rated as a safety measure. Provided this voltage sensing circuit remains intact, there will be no run away of the alternator.

It will be best if the battery end connection of the sensing conductor, is made at the fuse box and to the incorporated distribution bus bar connection point. There should be an existing white wire connected to this point, which can be used, so that physically accessing the fuse box is not required. This arrangement will achieve a tidy, workmanlike, electrically efficient job, without multiple connections to the battery terminal.

N.B. This new sensing circuit can not be broken, as a result of, for whatever reason, the blowing or opening of the fusible link, i.e. corrosion, mechanical disconnection, electrical blow out, or whatever.

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, possibly within the fuse box, but will require to be checked. I have no idea where the SBF (Sub Fuse Box??) is located and wired, so regret I can not advise in exact detail.

Unfortunately I have not been in a position to outline in physical detail all the required alterations, because I have not had exact information covering the factory installation, particularly regarding the termination of the original white wires at the battery/fusible link end, in spite of several requests.


You must take the time to read and understand all that I have posted, in order to do a proper job, regardless of the frustration and time this may involve.

[svxcess]

Originally Posted by Trevor

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, possibly within the fuse box, but will require to be checked. I have no idea where the SBF (Sub Fuse Box??) is located and wired, so regret I can not advise in exact detail.

SBF stands for Slow-Blow Fuse

These act as fusible links 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.

The SBF's are located in the fuse box under the hood. There a 7 of them, ranging from 30A to 45A.

See the alternator wiring siagram from the FSM. Look in the lower left corner.

.

[Trevor]

Originally Posted by svxcess

SBF stands for Slow-Blow Fuse

These act as fusible links 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.

The SBF's are located in the fuse box under the hood. There a 7 of them, ranging from 30A to 45A.

See the alternator wiring siagram from the FSM. Look in the lower left corner.

.

Thanks for the info.

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 component, linked to an external common conductor. :confused. The single line to the alternator, which in fact illustrates 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.

[Brandon770]

Awesome posts every one. I learned a lot from reading this.

[Johnybeas]

Ok, so as much as I've kinda been drowned with my lack of wiring knowledge, I've taken a few good things from this thread. Although, an atempt at "try(ing) that at home" will not happen. lol it is far too complicated for my minimal knowledge.

I am however, interested in getting a newer nicer wiring harness for in between my battery and alternator and all the areas mentioned in this thread. So my question is, can all the smart electrical engineers and the like on the forum to to some sort of consensus and produce an alternator wiring harness upgrade for a cost to those of us with decaying 1992 wiring who don't have degrees in electrical engineering or 30 years worth of experience?