The problem of maintaining the four batteries has already been solved. The next problem is that the PCM commands the glow plug control module on from the truck batteries, and the glow plugs will get there voltage from the glow plug batteries. I need to d more research.


Chuck

 

As someone has had to maintain four batteries, I also throw my hat in with the "don't" crowd.

Two 650-750 CCA batteries with 3+ year warranty, and use the warranty.

-blaine

 

The alternator is commanded to begin charging immediately and not held back by anything when the glow plugs are on.

<iframe width="560" height="315" src="http://www.youtube.com/embed/sTfun9Rzsuw" frameborder="0" allowfullscreen></iframe>

Josh

 

So you have experience, do you mind sharing. Why not?


Chuck

 

Just a hell of a lot of extra work, and a hell of a lot of extra money.

Unless you have a true NEED for either a bigger starting bank, or a separate bank for another application, it's more headache than it's worth.

Isolators can fail, in both directions -- either they're always on, or they're always off.

Then you have the problem of when one battery fails (without warning), it takes out at least one more; and you have that many more failure points to analyze before you find the right one.

In this case, the batteries aren't the problem, it seems... it's the fact that the alternator is only marginally capable of doing the job. If your glow plugs are staying on that much, try plugging the block heater in.

And no battery is ever supposed to be a "permanent" device. They're consumable, just like tires, brake pads, shocks, and windshield wipers.

Be glad you don't have to do them every year, like I did with the 4 on my Freightliner... that was usually a $400 job, in the dark, at 0300...

-blaine

 

I see........ It seems like I am just asking for more problems.


I do use the block heater. Anytime the temps are going to be under 50 deg the block heater is plugged in 2 hrs before start up.


Thanks for your input.


Chuck

 

i believe you.. my experience has been that when i crank,
dashdaq shows 9.5 or so for half a second, then as soon as
the engine catches, it's at 12.3~12.4, and after just a few
seconds, the voltage jumps to 14.6~14.8, and the engine
settles down to an idle that sounds like it's slightly under load.

now idling at 200 amps at 14.8 volts is 3.96 horsepower consumed.
four horsepower consumed isn't enough of a load to really affect
a 6.0, but the sound change is distinctive.

i'll have to make that video....

 

A quick google search resulted in lots of information on how much 7.3 glow plugs draw. Almost NO information on how much 6.0 glow plugs draw; only one post, saying about 10A per plug, for a result of about 80A.

The 7.3 folks have a set of glow plugs that pulls 200A(!) at initial startup, tapering off to about 110A before they're shut off.

In either case, you can easily see how our 105-110A stock alternator is woefully inadequate to the task. Even after the glow plugs are shut off, at idle, the alternator is still only JUST absorbing the load present from the running engine.

I'm curious as to why the factory engineers chose this route. Sometime it takes some somewhat convoluted logic to follow their train of thought, but this one is completely off the rails. Especially in a truck that has so many other electrical systems that are so very voltage-variance intolerant. I wonder if the alternator is a "parts bin" part that the factory bean-counters don't want to special-stock for the Powerstrokes, counting on the failure cost to be lower than the stocking cost?

It would be interesting to watch the glow-plug control with a scantool while watching the voltage.

Anyone know about the 6.4 and the 6.7?

-blaine

 

Install an inductive ammeter on one glow p[lug bank at one of the two harnesses at the Glow Plug Controller Module (GPCM). You can get up to 200 A draw at first, but then should stabilize around 35-45 A. Both banks should read the same. Each glow plug should draw 10-12 Amps after the initial current draw.

 

This is why I was thinking these trucks are so hard on batteries. That's 400 amps at first KO. Then the 80 amp draw plus the starter, and the FICM(prob 40 amps) and all other misc. electrical components. That's a heavy load.


Chuck

 

Here is Mustang_309's video of alternator amps at cold start


Josh

 

(Double post)




Josh

 

First I would like to say thanks for the response. Please don't take offence I am still trying to learn.
I think what you are saying is the alternator is charging but can't support the load.I will ask it this way.... When the truck was brand new did the charging system behave this way. Did the alternator put out 14v right away, or was there a 30 sec delay like there is on mine now. I did watch both of your videos on the other thread. One showed current draw but not voltage, so no power.

Thanks again, I really appreciate your input.

Chuck

 

The alternator cannot keep up when the engine is first started... Hence the low voltage while the glow plugs, electronics and everything else is running.

The stock 6G is marginal at best and even more so in the diesel.

You see in Mustang's video the normal running amperage was still near 60 amps when the GP cycled off. The 6G is rated at about 50 amps at 14.2 volts at idle. If it still needs to crank out 60 amps that's why it can only muster 13.8 volts at idle etc.

My video shows the "I" circuit is energized immediately to begin charging refuting the common belief that the alternator DOES NOT charge while the GP are active.

Josh

 

I really don't think Ford would put out a product with this design flaw.

I think what your are saying is if I took all but 50amp load away from the truck batteries, and put that load on other batteries not connected to the alternator, then the alternator would go to 14v without delay?


Chuck