That's the way it is. Ford started that in 99 with the Superduty 7.3. The 110 amp 6G is perfectly fine for Explorers and Rangers but when it comes to the glow plugs of the diesels and the electronics of the 6.0 it cannot handle it.

The 140 amp 6G should have been the standard alternator and should have offered an optional 200 amp as well.

I like the large case 3G, that's why I adapted it to my truck.

Josh

 

So even with your bigger alternator, it still can't handle the load. I have two alternators and it behaves just like all the others, it slowly goes to 14v after about 30 sec.

So with this design the truck is taxing on the batteries. The truck demands a lot of current at start up. So having two additional batteries dedicated just to the glow plug load circuit would be a good idea.

I think of all the design flaws of this truck, and ALL trucks have design flaws, this one is the most disappointing.

Again, Thank You for your input.


Chuck

 

no, it doesn't work like that. hook the OEM alternator up to a spinning
shaft, and spin it at the normal speed it spins at idle, and it will produce
13.2 volts, PERIOD.

with no load hooked to it at all. 13.2. THAT IS ALL THERE IS.

now for current to flow, there must be a difference of potential
between two points. if a fully charged battery, (which won't happen
with the OEM alternator) is hooked up to the truck, it'll read 12.6
volts or so.

that means that there is 1/2 of ONE VOLT difference of potential
to charge the battery with. so, you can use ohm's law which is
E=I x R to determine how much current flow will go into the battery.

the short version is, not much. the OEM alternator will only charge
the batteries to 11.8~12.1 volts. it's not enough. the batteries
die after a couple years. then you buy more motorcraft batteries.

THE ALTERNATOR ***MUST*** PUT OUT 14 VOLTS MINIMUM TO
PROPERLY CHARGE AN AUTOMOTIVE BATTERY. AGM BATTERIES
NEED 14.8 VOLTS TO FULLY CHARGE.

ford, and every other manufacturer has and will continue to put
out products with a design flaw both of this level, and far worse.

it's done all the time. it's called planned obsolescence. those front
rotors, that you can turn when you do brakes? used to be they had
lots of material to turn several times..... not any more. if you are
lucky, ONE turning. then you buy a new one.

'cause they can sell you more rotors that way. and it costs less
money to make a thinner rotor.

ever buy an inkjet printer? ever wonder why they build a cartridge
that only lasts 20 minutes, or four sheets of paper?

ford half assed a number of things with this engine group, in
their hurry to get to market. they have NEVER made it right,
just thrown slightly upgraded parts at it over time. the oil
cooler is a prime example. they "upgraded" it, by adding another
layer of fins.

so it last 10% longer. that is all. it's still a ****ty design.

take the new ford wonder diesel.... you get water in fuel, and it
sets the check engine light, and you can't erase that record from
the engine control computer. it counts them, and you get enough,
it voids the fuel system warranty.

the fuel system is then replaced at YOUR expense, not ford's.
it's an assembly, and parts and labor is in the range of $18,000.

welcome to the fine print. will that be cash, or charge?

 

So what your saying is the alternator is to blame for the short battery life, and not the heavy start up load. Good point, thanks.


Chuck

 

The lackluster alternator probably takes most of the blame for the short battery lifespan.

Keep in mind those amps while the glow plugs are on and normal system voltage and then somebody immediately cranks the heater on full blast and also turns on the headlights.

The alternator is already taxed out and the batteries are drawing down like crazy.

Also explains those that continuously will start their truck, move it 3 feet in the driveway, shut it off, restart it and then move it over to the other side of the driveway. Come back in 10 minutes and decide they want the truck facing the other way and then click click click click.... battery is dead.

Why? The whole time the alternator was never able to get the system voltage above 14 volts to adequately charge the battery and the batteries died.

So the ******** takes the alternator to his favorite parts store and they test it... guess what? It tests fine. Of course they are testing for 13.5-14.2 volts at idle which it does easily and also 14.2 at a simulated high idle and again it easily does the required tack.

So WTF says the ********, I guess my batteries are toast.

While the whole time the batteries were good and in theory so is the alternator.

What it comes down to is the alternator needs to be beefed up and also the operating habits of the owner need changed.

Josh

 

Well said, thanks.

I was thinking about taking some of the load off the truck batteries by adding two more batteries for just the glow plug load circuit. But if the alternator has problems with two batteries how will it handle four?

I guess knowledge is power in this case. I keep telling my wife to watch the gauges, and if your going to run it, run it for a half hour or more.


Chuck

 

I have 4 batteries and the system works quite nicely. I agree that battery isolators can fail and that it is an extra load on the alternator, but there are definitely uses for them. It is not cheap though ........

Not having to rely on battery powered tools or not having to cart around a generator that can easily get stolen is quite handy when out in the middle of nowhere. High idle, a 250A alternator, and 2 extra batteries are a nice platform for a 1500W - 2500W power inverter.

 

That is how I got the idea, when I read you had four batteries on your truck. I took a look at pics of your set up, very nice, clean set up.


Chuck