Just an update here for those following...

We remain working with Leece Neville/Prestolite on this issue, but sadly no updates on that front yet. Prestolite continues to indicate that what is going on is normal operation and nothing to be concerned about.

On our side, we tested out this other voltage regulator option being floated in this thread and sadly had materially worse symptoms.

It seems that the only options at this point are to deal with the issue (or 'issue' as Prestolite suggests it to be, lol) or switch to another manufacturer's line.

 

to me it sounds like that the reason we buy the LN alts is to get a more steady voltage flow in order to help keep the FICM from getting killed by the fluctuations that the stock one does.. but yet after reading through this thread the LN is doing it even worse at start up.. making me feel like not buying one when i find one on sale on ebay or from any other vendor..

 

I don't think it's the same issue Shawn, and somewhat self inflicted by the common enthusiast need for as Tim "The Toolman" Taylor often stated, more power, and we see that consequence.

Once the glow plugs are not in the command-on period the issues isn't there, and it's easily minimized with the normal pulley size and if the vehicle is prone to the issue, leaving the HVAC fan on a few notches. This alt has so much output that the additional load is not a hinderance, but a buffer.

Second, it's my opinion that is at the initial key on (buzz) and later at the starter engagement where I believe the FICM gets hurt since that's where the greatest amp draw occurs. It is only an opinion as I don't have the resources of Siemens to test the fragility of the FICM.

Ed, thanks for trying the stock regulator. But if you are doing your own testing the last time you said on your trucks you didn't see any fluctuations when installing the L-N 230a. Have you at all?

 

REPS sent to Ed for this latest update, and for running the test on the F605 green cover regulator... even if the test proved unsuccessful, and even if Prestolite does not recognize the reported issue to be of concern. Thanks Ed!

Sparky83... to my knowledge, there is no other alternator currently on the market for this application that is physically designed in such a way to reject the most heat, while producing the most electrical power at the lowest rpm while maintaining all rectification as well as rotating fans internally, than the Leece Neville 230amp.

It would be a shame to indict this alternator as bad, if the issue reported can either be resolved or determined to be merely a nuisance but not a concern.

Denso segmented conductor alternators, the so called 6 phase hair pin stator type that Ford moved to in 2008, which put the Denso 96 segment technology inside a 3 bolt T mount frame that inspired the aftermarket rebuild distributor supplier Romaine Electric to put together a retrofit package for alternator shops like DC Power, Mechman, MeanGreen, and the like to sell for pre 2008 Fords like we have... is a good way to go also. The fans and the diode bridge remain inside the alternator, as opposed to the Mighty Mitsubishi, a 35 lb monster with an external fan, or the venerable USA made Penn-Tex with an external fan and an external box and harness for the rectifier, and perhaps even the regulator (I forget at the moment).

I'm looking to replace my perfectly functioning 110 amp secondary alternator, which is why I still keep up with alternator battery threads. To get away from diesel idling to maintain battery charge while using battery operated equipment while stationary, I'm throwing more lead, copper, and rotating electrical under the truck to bring it all back to life when driving. I already have an L-N mounted up top, but another L-N would be too big for the space available down below. I don't want external fans or external harnesses, even if those alternators that have them offer superior performance. As always, it is a matter of balancing interests.

I'm giving the Denso designs a close look, but do not want to deal with DC Power etc. Since there are two different Denso rotor and stator diameters available in a Ford T mount, two different frames, and several different regulators with different connector profiles and clocked positions, I'm leaning toward building a custom unit to suit my fitment application (lower secondary).

 

Deleted -- Y2K was typing my answer as I was typing my question... Thanks Y2K!
Scott

 

dont get me wrong i wasnt trying to say L-N makes bad ones or anything like that.. like all alt mfg im sure the one people are using on the 6.0's are made for more than just 1 specific application and that theyre trying to please the medium. and since i just have had the factory alt and never had a L-N i can only go off what ive been reading in various threads and forums..

Of what ive been reading here in this thread it just sounds like people are trading out one set of issues caused by 1 alternator with another set of issues caused by another..

since i bought my truck all anyones ever said to me was "Junk the stock alt and get a L-N or else its going to kill your FICM..." (matter fact its usually the first comment someone makes to me once they find out its on there).. Despite my volts staying steady between 12.5-13.5. i rarely if ever see it at 14 even with everything off. more times than not i usually see it sitting between 13.2-13.5v cruising on the highway or city streets.. normally when ill see 12.5-12.8 is when the headlights are on at night..

Then i started finding threads like this one all over different forums where people are now having issues with the L-N.. it just makes me wonder why should i get one if all im doing is just trading one problem for another?

 

I think the majority of users are well served by a 140a unit with the small pulley. For all vehicles the engine controls once running are pulling 18a, the stock pickups will pull at maximum of 70a with everything on, although in the first 10 minutes of running its an additional 50a going to restock the batteries with a taper down. So if we can wait about 1 1/2 minutes after cold starting, something we should be doing anyway with a diesel, you won’t be in a bad place.

Again, the only issue with the L-N is it overcompensates voltage so things get funky with the glow plug controller during the first 100 seconds of cold start. Run the stock pulley and flip the fan on during that time. You’ll still have higher voltage then the 110a or the 140a.

 

i wanted them to install the 140 when my alt took a crap and killed the batts but the dealer said there was no such thing and just threw the 110 in there.. despite i gave them the fricken part number for it.. why i have a love hate relationship with warranty work.. they wouldnt warranty the new batts that were to replace the warrantied 1yr old dead batts unless they put the alt on.

i normally have the blower set on high for the defrosters just so i dont have to deal with foggy windows when i get in the truck.. in the summers the AC's usually on..

 

Thanks for the update Ed. I have resigned myself to the fact the L-N sees this as "normal". I still need to decide if I hate the oscillation enough to consider this alternator "desirable".

My thoughts on 230a alternator was a Tim The Toolman moment. My plans had me thinking I may need more than a 140a can provide but it wasn't a need. I just wanted more power!

Also to be clear I don't think of this as a "oh my god my truck is going to explode" issue or maybe not even an "issue" at all. It certainly is an annoyance and a big one to me personally. Others might see it as a no big deal.

 

To clarify the point, Prestolite is seeing as normal a voltage output of 14.5 to 14.6 volts.

 

If you are using AMG batteries I think you might need a different regulator. I'm not sure on this thou. I believe I read it in one of the Mercruiser bulletin a couple of years back.........but I've been wrong before.

 

I see mostly 14.4 at the alternator/battery, and 14.2 in cab (at PCM, not at cig lighter). And, from time to time, 13.9 in the cab, also at PCM. I've never seen 14.6. I'm running Revision E, although the Prestolite revision notes that I have seen do not indicate any regulator changes through the first five revisions (at least that were disclosed).

 

i know optima said their batteries will have issues when charged higher than 10amps using a charger... alts they say no limit applies for the amps... but for all charging situations they recommend not going higher than 15v... Float charging they say no higher than 13.8v..

 

Posted without reading ....

 

Just to show how variable this entire LN situation can be, this was from the earliest test recordings I did when deciding to do a video comparison, then after completing all the work over 4-5 months decided I didn’t like the format and started over. This was never on the net before.

What problem.....



Because of the warmth, engine idle was low and the alternator reacted to the temp with its output staying in Ford range. As I’ve said before, I never saw the issue with the large pulley during most of the year. Even a goose didn’t upset the cart.