High Output Alternator Resolution Discussion

hite337

hite337

Hite Performance
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As many of you know I have a GEN1 LSE and I have converted my hydraulic cooling fan to electric. This extra 18 amps from the electric fan has pushed my factory alternator to its limit. I recently added a pair of 12" subs and a 200 watt RMS amp to the equation. At night I am having issues with the headlights dimming so I know I am pushing my factory charging system past its limits. I have installed several brands of high output alternators with no success. I later learned that the LS's PCM controls the alternators output to the battery. This presents a problem because the PCM will not let you benefit from the extra amperage and/or current provided by the HO alternator.

I am asking the community at LVC to use this thread as a 'brainstorming' session to find a resolution to this issue. I know alot of us would like to install HO alternators in our cars but we dont have the ability to do it correctly. I know QuikLS had an alternator from Ohio Generator that he claimed worked fine. I dont know if anyone has any specifics on this alternator but if anyone knows what makes it different this is a good place for that info.

If anyone has ideas please post them them here and I am willing to experiment. I will be ordering a HO alternator this week and I am determined to make it work. If anyone is in contact with Torrie, ILLS or another tuner maybe you could ask them if this is something that can be changed with the SCT tuner. I do not have an SCT...yet...but I am planning on purchasing one very soon.

I am not an alternator expert so I am asking for a little help here for the good of the LS community. Maybe this issue can be resolved with the SCT but if not, lets figure this out!
 
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Im also interested in this, I have a massive audio system going in and am in need of a alternator solution. I don't see a reason why you couldn't just unhook the wire to the PCM harness, don't most alternators have built in voltage controls? Correct me if im wrong here.
 
If, as you say, the PCM is controlling the alternator output it is not only limiting voltage but current as well. You then would be better served talking to one of the tuners mentioned to see if the code could be changed to allow more current under demand. All the high output alternators in the world will do no good if the regulator is current limiting.
Another thought on the matter is the current flow is limited as protection to keep the smoke in the wire harness and electronics. A possible workaround is a secondary system with a stand alone regulator to feed you additions.
 
Ancillery said:
Im also interested in this, I have a massive audio system going in and am in need of a alternator solution. I don't see a reason why you couldn't just unhook the wire to the PCM harness, don't most alternators have built in voltage controls? Correct me if im wrong here.
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I dont think simply un hooking the wire harness will work without the 'check charging system' warning message coming on. I do not think these alternators have a built in voltage regulator.
 
Hite - been snooping around this forum for more a year now and finally decided to get in the mix to resolve this issue. To answer the SCT question -- Yes, I emailed Torrie and he says he does have some alternator control, but I need to let him know the exact issue, and what I want him to do.

His last response was, "Ok, I have some alternator control but I need to know what exact problem I
am trying to solve first and foremost."

Take care,
Mr. Torrie - Owner



To give you the short, I have an 02 LS V8 with electric cooling conversion ran by a flex-a-lite 31165 controller. Alternator went out and decided for HO upgrade, saw the mention of National Quick Start on another thread. Went with 160amp dual rectifier.....same scenerio and there's a whole other issue I'm going through as far as their customer service but that point is moot.

If you can tell me what I need to pass along to Torrie as far as altering the PCM's communication with the voltage regulation, I will see if we can come up with a strategy.
 
I can't be of much help but has anyone considered the by product of raising the pcm's alternator output to the battery? Or will it simply only affect that.
 
Broseph said:
Hite - been snooping around this forum for more a year now and finally decided to get in the mix to resolve this issue. To answer the SCT question -- Yes, I emailed Torrie and he says he does have some alternator control, but I need to let him know the exact issue, and what I want him to do.

His last response was, "Ok, I have some alternator control but I need to know what exact problem I
am trying to solve first and foremost."

Take care,
Mr. Torrie - Owner



To give you the short, I have an 02 LS V8 with electric cooling conversion ran by a flex-a-lite 31165 controller. Alternator went out and decided for HO upgrade, saw the mention of National Quick Start on another thread. Went with 160amp dual rectifier.....same scenerio and there's a whole other issue I'm going through as far as their customer service but that point is moot.

If you can tell me what I need to pass along to Torrie as far as altering the PCM's communication with the voltage regulation, I will see if we can come up with a strategy.
Click to expand...

The issue I have noticed is when you rev the engine the headlights get very bright for a split second and then go back to normal. So I'm worried about burning headlight bulbs out very quickly. It also makes me wonder how well the alternator is actually charging the battery and supplying the car with power.
 
hite337 said:
The issue I have noticed is when you rev the engine the headlights get very bright for a split second and then go back to normal. So I'm worried about burning headlight bulbs out very quickly. It also makes me wonder how well the alternator is actually charging the battery and supplying the car with power.
Click to expand...

I had the same exact isssue. The headlights at idle and cruising are normal and then raise the rpms and Voila! power of the sun. Im not worried about bulbs-- it's the 11.8 volts and dropping at idle that worries me. This is because whatever is communicating the PCM to alt is not letting it charge the battery until the RPM's are raised.

I'm betting that there is a voltage sensor for the battery that is keeping the PCM from allowing the alternator to power within it's optimal range (the same regulator that is keeping the battery from overloading). What baffles me is that the LS isn't the only vehicle to have this setup up. It's not some conspiracy car with radically different electronics unlike any other, and I'm sure that HO alts are built for newer GM and other Fords with far more electronic engineering that work just fine.

What I need to tell Torrie is what he needs to do to the PCM to "unlock" the regulation or to configure it to an "ideal setting"....this is where Joegr might be helpful.

Or we need to figure out why only Ohio Generator, if Quik's statements are true, could come up with a proper alt.
 
Im not electronically gifted and schematics are not my forte. If someone has the schematics and know-how of the entire voltage system. We could figure out what is blocking out the alternator and possibly lock it out with the SCT.
 
Dc Power Inc claims to have HO alternators that will work with the PCM controlled regulators but they start at $440 and they don't list one for the LS. I am going to call them Monday and see what they do to work around this issue
 
Broseph said:
Im not electronically gifted and schematics are not my forte. If someone has the schematics and know-how of the entire voltage system. We could figure out what is blocking out the alternator and possibly lock it out with the SCT.
Click to expand...

It's simpler than that. The PCM controls the alternator, and it expects the alternator to work in a particular way. You can't lock it out, because then the alternator wouldn't work at all. (This applies to gen I, gen II is different.) An alternative would be to have an alternator with internal regulator made. You would have to rewire the connections to the alternator, and the PCM would always be upset and the battery light would be on all the time.
 
joegr said:
It's simpler than that. The PCM controls the alternator, and it expects the alternator to work in a particular way. You can't lock it out, because then the alternator wouldn't work at all. (This applies to gen I, gen II is different.) An alternative would be to have an alternator with internal regulator made. You would have to rewire the connections to the alternator, and the PCM would always be upset and the battery light would be on all the time.
Click to expand...

Maybe we could have an alternator made with an internal regulator and then have the SCT take care of the battery light. I'm not an expert and I am not sure what all the SCT is capable of. Just throwing out Redbull/Vodka thoughts.
 
joegr said:
It's simpler than that. The PCM controls the alternator, and it expects the alternator to work in a particular way. You can't lock it out, because then the alternator wouldn't work at all. (This applies to gen I, gen II is different.) An alternative would be to have an alternator with internal regulator made. .
Click to expand...

According to the service manual it is an internally regulated alternator. The guy of National Quick Start I've been in infrequent contact with believes the issue lies in their alternator's (aka "disco ball generator") stator not being adequate to create enough current at idle...I took that explanation with caution, but I'm fairly confident the units are internally regulated--hence the complication because if it's all PCM controlled, we should be able to signal it to do whatever we want easily.
 
When I need my alternator replaced I went to my guy I have been using for over 20 years. That is all he does is alternators/starters ect. He said he has not seen any good results with trying to upgrade the style alternator we have, not sure which style they consider it but mentioned that the 6G style they use in alot of newer cars will put out 100 amps at idle. I dought there is any direct fit ones but not sure. Also maybe different size pulley if one is availible to spin alternator faster at idle.

I dont have an electric fan in mine but with the stereo I had idle issues with lighting and such, added the second battery and works very well.

The diagram is for 2002 LS 3.9

ls charging system.jpg
 
GM has no problem with their current regulating setup. Their system simply turns the alternator on or off according to the needs of the vehicle. It will try to not run the alternator on acceleration or cruise, and will try to do all its charging on decel. Of course, if the power drops outside its specs then it will run the alternator as needed regardless of what the engine is doing. If you add a higher power alternator to the system, it doesn't care. If you put high load equipment on, it doesn't care. It only cares that the vehicle's battery doesn't get discharged too much. The alternator's internal regulator will not allow the alternator to make more power than is needed, just as it did in the pre-computer days.

I can't imagine why Ford would go through the hassle of trying to map out an expected load vs RPM for an alternator either, because they'd have to have a usage map to take into account high load things like electric seats, rear defogger, ect and that would get very complicated very fast.

The alternator's build method as being a more probable cause. High output alternators will have more windings in a smaller space, meaning smaller wire. It takes more engine RPMs to induce current into more windings, which means the initial RPMs must be higher. When I had the alternator on an S10 pickup rewired for more power, I had to compensate for the low idle characteristics by installing a smaller pulley on the alternator. It increased the alternator's low speed RPM enough that I was getting power out of it, and this was an unregulated system in that the PCM had no control over the alternator's operation. The alternator's internal regulator did it all.

I would suspect that the only problems with putting a high output alternator on the LS would be the very same low RPM characteristics of the alternator and not the PCM, and the fix would be to either get a high output alternator that has good low RPM characteristics (read larger body) or put a smaller pulley on the rewound factory size alternator. If you wanted to calculate it out to see what size pulley you need to spin the alternator the same at idle as it does with the factory pulley at 1000RPM you can, but a 1/2 inch smaller diameter pulley should do the trick. You want to make sure that regardless of what the pulley RPM is at idle that you don't exceed the alternator's max RPM at the engine's max shift point RPM. A smaller accessory belt will also be needed with a smaller alt pulley.
 
Broseph said:
According to the service manual it is an internally regulated alternator. The guy of National Quick Start I've been in infrequent contact with believes the issue lies in their alternator's (aka "disco ball generator") stator not being adequate to create enough current at idle...I took that explanation with caution, but I'm fairly confident the units are internally regulated--hence the complication because if it's all PCM controlled, we should be able to signal it to do whatever we want easily.
Click to expand...

Gen II is internally regulated. Gen I is PCM controlled.
 
The HO alternators I have tried had the underdrive (smaller) pulleys on them. What I didnt try was the smaller pulley on the factory alternator or the larger pulley on the HO alternator. I dont know if this would make any difference but when I get my HO alternator delivered I do plan on trying this just to satisfy my own curiosity.

I ran across an item called a MLA module. I had never heard of it but it is supposed to keep your alternator charging at a higher volatage. They even claim to make them for the Ford G series alternators.
http://www.missinglinkaudio.com/id18.html
Heres a link to a misc review on the MLA moudule
http://www.caraudioclassifieds.org/forum/car-audio-product-reviews/8284-review-missing-link-audio-module.html

Also available is the XS Power VCM (voltage control module). It seems to be the same thing as the MLA module but has a dash mount interface and is fully adjustable whereas the MLA module only has 2 presets. They have models specific to some GM alternators but the link below appears to be a universal fit.
http://4xspower.com/shop/electronics/xsp310-vcm-digital-dash-mount-controller/

I am wondering if these modules could be used to compensate for the PCM controlling the alternators power output? I will be calling XS Power on Monday as well as DC Power Inc.
 
What about adding a second alternator?

Would be hard to as there's not much space but that seems to be the only fix.
 
BlackLS06 said:
What about adding a second alternator?

Would be hard to as there's not much space but that seems to be the only fix.
Click to expand...

Seems reasonable. Maybe where the fan hydraulic pump would be?
 
BlackLS06 said:
What about adding a second alternator?

Would be hard to as there's not much space but that seems to be the only fix.
Click to expand...

joegr said:
Seems reasonable. Maybe where the fan hydraulic pump would be?
Click to expand...

I have thought of this and if a HO alternator resolution is not found then that will be my next course of action. I do believe that a second alternator can be mounted where the factory hydraulic fan pump was located. The space is very tight but I do think that it can be done by fabricating a bracket to use the existing bolt holes in the engine block from the fan pump. The second alternator doesnt have to the same size as the factory one, 60-80 amps would be fine I think. so therefore the physical size could be smaller to accomodate the tight space.

The question I have about this is do I use a 2nd battery with the additional alternator to power the amp, electric cooling fan, etc or can I just run another power wire from the 2nd alternator to the existing battery?
 
joegr said:
Gen II is internally regulated. Gen I is PCM controlled.
Click to expand...

Seems we are both correct. It is internally regulated BUT the PCM takes information from the generator load to determine the optimal set point that is correlated to the regulator.

As if it's not confussing enough, these circuits are "unidirectional" working in pair to regulate voltage. The only promising thing Ive read is that these are pulse-width modulated. IIRC you helped a LVC member read similar signals to develop a cicuit to run a electric fan off the factory hydrolic connector...maybe the same can be done to adjust the signal to whatever alternator size one has.

Or I could get with Torrie to see if there is a way to manipulate the "Circuit 10-BA25" or "GEN COM" circuit which is the PCM C175c to alternator C102a (Pin 2) circuit that is the communication line from the PCM to voltage regulator to determine the optimal set poin

Again...if someone has any idea of what I should be asking Torrie to do with a 160 amp alt maybe we can do this with the SCT.
 
hite337 said:
I have thought of this and if a HO alternator resolution is not found then that will be my next course of action. I do believe that a second alternator can be mounted where the factory hydraulic fan pump was located. The space is very tight but I do think that it can be done by fabricating a bracket to use the existing bolt holes in the engine block from the fan pump. The second alternator doesnt have to the same size as the factory one, 60-80 amps would be fine I think. so therefore the physical size could be smaller to accomodate the tight space.

The question I have about this is do I use a 2nd battery with the additional alternator to power the amp, electric cooling fan, etc or can I just run another power wire from the 2nd alternator to the existing battery?
Click to expand...

My only concern is that the PCM will not recognize any load necessity for the factory alt to operate at its regular setting from the battery load sensor; therefore, canceling the addition alternators imput. It would be much more costly and aneurism inducing to do this than buy an Ohio Gen alt for $700 or have an SCT strategy

I could imagine the bloody knuckles mount a custom braket and alt in that spot. Just had a palpitation thinking about it:Bang
 
Broseph said:
Or I could get with Torrie to see if there is a way to manipulate the "Circuit 10-BA25" or "GEN COM" circuit which is the PCM C175c to alternator C102a (Pin 2) circuit that is the communication line from the PCM to voltage regulator to determine the optimal set poin

Again...if someone has any idea of what I should be asking Torrie to do with a 160 amp alt maybe we can do this with the SCT.
Click to expand...

I dont know what to specifically ask other than "can he write code to allow a 200 or 220 amp alternator to work with the LS PCM". DB Electrical and PowerMaxx make alternators that are rated at 200 and 220 amps and are fairly inexpensive. I know that you have to 'pay the cost to be the boss' but if we find an inexpensive solution then I'm all for it.

I would be fine if Torrie could somehow bypass the PCM altogether and we could run an external regulator on the HO alternator. Maybe somehow 'trick' the PCM into thinking the alternator is putting out satisfactory numbers. I dont know if this is possible (or even a good idea) because of how the PCM controlled charging systems work. It would be nice if Torrie could just raise the value the PCM needs to be satisfied but I'm sure thats easier said than done.
 
I know this is a somewhat Gen1 centric thread, but if the Gen2 is *NOT* PCM controlled and using a simpler internal regulator then fabricating a bracket to bolt on a 3G/4G alternator and swapping over a wiring harness would be the solution there. Just need to find an alternator with a relatively compatible size and layout.
 
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