Sometimes people that help want to see some very specific numbers - in this case, it is the glow plug amp draw several seconds (or longer) after turning them on (the amount of time they stay on is influenced by several factors - oil temp being one). Looking at the amp draw seems to be more specific to troubleshooting your issue than looking at battery voltage. It is the nature of the system to draw a significant amperage load at first, but that SHOULD drop down fairly quickly, and then turn off. Unless I am mistaken (and I may have missed it), it hasn't been proven yet that they drop like they should OR turn off. The people that request specific data tend to be the ones that are better at troubleshooting than the average person. Right or wrong, you can get more help by supplying the requested information. Just my 2 cents.

 

Duuuude!!!! I'm asking if you've checked if the glow plugs are staying on the entire time the truck is running!!!!!

And please don't buy any more vehicles.

 

I believe this is quite common. (Failure to communicate, that is)

 

I hear it quite often at home.

Although not quite as much as from the first wife with a sweet southern drawl.

 

when you go to start it next time use you booster cables and hook 1 cable to the negative on the battery and hook the other end of that cable to a bracket or some type of grounded part on the engine... see if that works... sounds like a bad ground to me...

 

It’s not a bad ground.

 

He needs to put a DC Clamp-meter on the GP power lead and see when it shuts off.

 

Yep. I don’t see where anything else can pull down the electric supply and hurt the batteries. Not sparking on disconnect and not a high draw after shutdown.

Other then that there must be some residual effects when this unseen truck made it through the wormhole. Put a set of batteries in and those electrons just go back 16, 17 years.


It might not be the problem, but it should be checked.

 

Yeah....After my EGR cooler failing catastrophically after only 40,000miles, I would say thoroughly flush and replace(or delete) the EGR cooler too!!

 

As I stated before, twice, the glow plugs turn off within 30 seconds of the engine starting. They are not staying on. They draw roughly 150 amps, the initial draw is slightly higher, then it tapers off to about 144 amps throughout the cycle of the glow plugs. The truck I just bought does exactly the same thing, as does my 97 7.3L. I'm not talking about how long the light stays on, I'm measuring the amps via probe at the relay. The longest I've measured them staying on was about 47 seconds and that was when it was below freeing outside. Regardless of outside temp they don't stay on long at all once the engine starts. The gp relay turning off coincides with the jump in charge volts.

The glow plugs are working fine, they come on, and go off, the length of time they stay on is affected by engine temp. They go out faster when its warm outside. Usually too fast to get from the key to the front of the truck to read the meter.
Keep in mind this truck sits in a garage, its rarely dealing with a super cold start. The coldest Ive seen the garage get is around 50 degrees over near the one door. The place has a heated floor that's powered by the boiler in the house 80 feet away. Its not meant to 'heat' the building, just keep it from freezing in there. This winter has been pretty warm, its likely in the mid 60's in there right now even though its only 29 degrees outside.

Today was the third day it sat, before retesting the glow plugs, the battery voltage over that period dropped .01 volts per day.
There is no significant residual draw,
The glow plugs are not staying on, and the relay is working as it should.
The alternator has been tested and retested,
the starter draw is normal.

Having the second truck gives me a baseline to compare to,
I bought the second truck a pair of batteries, changed the oil and filter, pumped the fuel tank and changed both fuel filters today.
It started up after about 10 cranks and idled fine. No codes, no check engine light, etc.
I pulled all four wheels, took all four down to the tire store and had four new tires mounted up. I checked all the caliper slides, topped off all fluids and took it for a ride.
So far so good. I ran it about 30 miles this afternoon mostly at slower speeds on back roads to give i some run time.
It charges fine, everything seems to work as it should.
The two batteries I used were the two 750cca Interstate batteries that came from the other truck. After driving it today the battery voltage in that truck after being parked for about an hour is 12.42v.
The batteries were right off the charger from last night, they were at 12.55v when I put them in the truck. I started and stopped it about four times today and drove it for about two hours while running several errands today. The second truck is showing a .028 amp draw on the battery sitting. Most of today's driving was with the lights and wipers on with the radio playing. The longest sit time was while at the notary getting the tags. Maybe about 40 minutes or so. It seemed to start fine each time.
The only thing I found odd is that the windshield had some oily looking droplets all along the top edge, they were clear and smeared when touched. I thought at first it was water leaking but they weren't water. More like oil. I washed the windows and nothing reappeared. The droplets were slowly running down the glass on the inside but only at the very top. The defroster didn't dry them up or affect them. Maybe something from the plastic gassing off?
I ordered a new fiberglass cap for the second truck, until it gets here I parked that truck down back in the other garage. They told me four to six weeks on the cap.

I didn't plan on buying the second pickup, but it was cheap, and had low miles. Too cheap to pass up.
I am really looking for an older 300 6 cylinder manual trans truck, but it has to be low miles and clean.

 

I never made it past your first paragraph because a 6.0 GPCM doesn't pull the amps you say they do. I’ve got over 20 recordings with different alternators from 110, 140 and 230 amps of the start up of a 6.0 all doing the same thing. Not the amps, and while time may be variable, not the time. And I’m not the only one who has recorded amp draw and voltage when starting.

No proof of life, I’m done.

 

I have both trucks here side by side, its 57°F in the garage. With a Snap On amp probe on the cable both of these trucks show me only 136/138 amps draw when the glow plugs are one, that draw goes away less than 10 seconds after the engine starts.

The charge volts aren't the problem, the problem is that the batteries simply do not gain charge when the engine is running even though there's obviously battery voltage and amps at the terminals, even if I leave it sit at high idle for an hour. The voltage in the battery is lowered to 12.15 on the first truck, and 11.99 on the second truck. The second truck recovers battery voltage after about 16 minutes, the first truck does not, the battery is only up to about 12.22 after running for a hour. The charging voltage at those batteries is 14.4 to 14.7 volts. When I shut the truck off, the battery voltage goes from 14.7 and quickly drops to 12.3 or so, and will continue to drop if not fully charged. With or without the cables connected. Its as if the truck is using more power than the system can provide.

Both trucks revert to a high idle on their own if left running. They jump up to about 1000 to 1100 rpm.
Both trucks have the 110a alternator
Truck 1 was built 11/02, Truck 2 was built 1/03.
The only real difference between truck 1 and truck 2 is that #2 has heated seats

.On both trucks, with the engines warm, and the glow plugs off, if I turn on the headlights, heater blower, and radio the battery volts drop to only 12.15 or less at idle.
Even with fully charged batteries, on both trucks, the headlights dim at idle at night. If I connect a trailer, the added lights and onboard battery drop the charging voltage to less than 12v, although the amps climb to near 100 with the trailer brakes applied. None of this happens with my 1997 F350. If I were to only drive at night all week, the 03's would both likely go dead pulling the trailer with the lights on. The alternator simply does not keep up.

Both trucks have .023 and .024a of battery draw at rest.
Truck 1 starts faster than truck 2, Truck 1 starts almost instantly if the cranking speed is high enough, truck 2 takes about 3 or 4 revolutions to fire up.
I haven't done any serious testing but truck 2 seems harder on fuel.

I'm going to look at an 04 F350 tonight, its a low miles truck that go hit and repaired. They changed the bed but it didn't get repainted. The guy drove it here from out west and his neighbors are giving him grief over owning a diesel so he has to sell it. It'll give me a newer long bed with low miles. Its supposed to only have 23k on it.
The only drawback is that it won't match any of my other trucks which are all either black or white, this one is silver.
I wish it were an older model but for the price, I can always paint it, then flip it to make a few bucks on it.

 

Here is an idea, when you start with 2 new batteries again take you volt meter to the store and get the best two. When you get home DO NOT use any of your chargers. Let's see what happens.

 

I did that with he first set of Deka batteries, and the first set from Walmart back in Nov.
If the chargers were at fault I'd also be having issues with all my other vehicles and batteries.
I've also bought and tried three different battery maintainers, all which seemed to be about the same with the exception of the
Schumacher SC1319 which overheated constantly and never seemed to shut off. It wouldn't handle two batteries. Which has been another issue on trucks with two batteries.
In order to put them on a maintainer when parked, the batteries have to be disconnected or at least one needs to be separated so two maintainers can be connected to keep both batteries fully charged. Its not a big deal on a vehicle that's going to sit for say 6 months or a year, but its a royal pain if its only sitting for a few weeks.

 

No offense but i cant tell if your off yer meds or something.
The best guys on this forum have asked for pics of the situ and your not doing it.
Why the resistance of this simple request.
You either want help or want to tell us about all the cheap 6.0s your buying.
Which is it?