Keith's M1078 Project

coachgeo

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Grom looks like a real good shuttle bike choice. My..... (oops.- gotta get back to civilization after putting truck on its side oorr some other stupid whoops) shuttle bike is also planned for high mileage... but its bit bigger KLR and achieves high MPG by being powered via a 10HP diesel.... you make me doubt myself now lol
 
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chucky

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Testing the motorcycle lift. View attachment 841661View attachment 841662Yes it’s going to hang out a little and I haven’t fabricated the track mount for the motorcycle instead I shifted all my work to the interior of the habitat. If your wondering about the bike it’s a Honda 125cc Grom that I changed all the plastics, also going to put some off-road tires on it. I chose it for the size and fuel mileage (100 mpg) my wife and I fit on it comfortably.
Just a quick couple of questions about the truck ! Do you have any kind of security/ camera system in your back yard? Or any big mean dogs? or you have guns in the house ? I wouldnt want to travel that far to get all skint up trying to relocate your truck when your done with it!
 

Keith Knight

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Jump Starting the FMTV!
Yesterday I attempted to start my truck and the batteries are dead again, understandable they are 6 year old batteries. A quick trip to Sam’s club 4 new group 31C batteries and one of those small jumpstart boxes only 3.5”x1.5”x8” 12vdc. On the way home I thought maybe I can use the new jumpstart box connected to the 12v side of the batteries, with the understanding that you can actually charge all 4 batteries using a 12v charger. If you don’t believe me try it it works. Crazy enough hooked up that little jump box to the 12v side and it cranked right up! 😳 Turned it off and started it again. I’m sure others may know but I’ve never read it before and wanted to share the info.
 

chucky

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Jump Starting the FMTV!
Yesterday I attempted to start my truck and the batteries are dead again, understandable they are 6 year old batteries. A quick trip to Sam’s club 4 new group 31C batteries and one of those small jumpstart boxes only 3.5”x1.5”x8” 12vdc. On the way home I thought maybe I can use the new jumpstart box connected to the 12v side of the batteries, with the understanding that you can actually charge all 4 batteries using a 12v charger. If you don’t believe me try it it works. Crazy enough hooked up that little jump box to the 12v side and it cranked right up! 😳 Turned it off and started it again. I’m sure others may know but I’ve never read it before and wanted to share the info.
My solar panels stay on all the time which charges my house batteries in the shelter and those 12v batteries feed the 2 12v batteries on the truck and like you said for some reason that keeps the 2 24v batteries hot in the truck batteries
 

Third From Texas

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I'd have figured that it would require a balancer to populate the charge across all four. Know that 99.9999% of the time with these trucks the 12v side is too low due to the damned 12v vampiric leak they all suffer. So a single charger hooked to one battery with a balancer would bring all four back to life.

Never would have thought that it would work w/o a balancer.

Cool
 

Mullaney

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Yeah, anybody figure out the 12 volt parasite?
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Sad to say, in a year for me - No. Best solution is to crank the truck and make about a 20 mile "loop around the block".

I messed. I metered. I measured. I rewired the batteries with new cables. None of that solved the problem. The new cables made it so the charging system is more effective. Everybody keeps saying DRIVE THEM and I am starting to believe that really is the solution. The 12v side is always where the problem shows itself.

Jumpering with a second MV and a NATO cable solves it quickly too.
 

coachgeo

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Ron knows about as much on the topic as anyone I've seen post. He's had some interesting perspectives.

There's the trans computer that is always on, but at the end of the day a battery disconnect solves all.

:)
in the A1's.... seemingly not true based on recent discussions..... battery disconnect removes the micro charge for the ecu in A1's ... apparently ecu battery dies and they are not replaceable..... and/or you loose settings if it does not die from it.

IMHO on top of driving it....Dont care if it is A0 or A1.... put a solar charger on it or AT LEAST a "good" battery balancer on it. Un balanced batts really work the alternator HARD.....and alternator is what??. twice, three times, the cost or more of 4 new batts.
 

Third From Texas

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Can't say, don't have an A1. Mine's an A1R with a battery disconnect. and it sure as hell safely stops the drain when the battery is disconnected. I also know that a battery disconnect works fine in an A0 truck. Want to test it? Go pull your battery cables for a day. Hook them back up. Truck works fine.

So you (or someone) are saying that an A1 that has sat with dead or no batteries installed for an extended time has a brick for an ECU as a result? Because that's likely over 90% of the A1's coming out of the various auction houses.

Agreed on some sort of tender (solar, 120v) combined with a balancer. But at the end of the day, it's still almost ALWAYS the 12v side that 'leaks" not the 24v side. Interestingly enough, the dual voltage Niehoffs are not "balanced" to begin with (note the output on the various sizes, always vastly higher on the 24v rail with only a couple exceptions). So I suspect it's not quite that simple. If the 12v side is inherently low on these trucks, you would expect the alt to push out more on the 12v output side (yet the reverse is always true by design).

Again, not my expertise, thus I mentioned Ron.


btw: unless the truck is parked up in the arctic circle, four batteries is overkill, so there is little reason to ever replace four new batteries
 

Mullaney

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Can't say, don't have an A1. Mine's an A1R with a battery disconnect. and it sure as hell safely stops the drain when the battery is disconnected. I also know that a battery disconnect works fine in an A0 truck. Want to test it? Go pull your battery cables for a day. Hook them back up. Truck works fine.

So you (or someone) are saying that an A1 that has sat with dead or no batteries installed for an extended time has a brick for an ECU as a result? Because that's likely over 90% of the A1's coming out of the various auction houses.

Agreed on some sort of tender (solar, 120v) combined with a balancer. But at the end of the day, it's still almost ALWAYS the 12v side that 'leaks" not the 24v side. Interestingly enough, the dual voltage Niehoffs are not "balanced" to begin with (note the output on the various sizes, always vastly higher on the 24v rail with only a couple exceptions). So I suspect it's not quite that simple. If the 12v side is inherently low on these trucks, you would expect the alt to push out more on the 12v output side (yet the reverse is always true by design).

Again, not my expertise, thus I mentioned Ron.


btw: unless the truck is parked up in the arctic circle, four batteries is overkill, so there is little reason to ever replace four new batteries
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Yeah, My nice square "factory" batteries were stolen shortly after the truck arrived here. I ended up replacing those batteries with four 27 series batteries. Worked great until I let it sit too long, so on the 12v side it was really low. It seems to be that the starter runs on 24, but whatever energizes that circuit is 12v. I can hear what I would call solenoid chatter. Stop, go get the passenger van and attach a set of jumper cables to the 12v string and the truck fires right up. Drive for 20 minutes and life is good.

OR, crank it at least once a week and the problem doesn't rear its ugly head.

The other S & S truck that I have still has the factory squares in it. For whatever reason, there are only two. I assume the PO removed two. Or removed all four and only installed two in their place. Extra wires for battery 3 and 4 are just laying in the bottom of the battery box. Strangely 3116 vs 3126 is the big difference and that older truck cranks reliably every time - even after sitting for two or three weeks.
 
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Ohiobenz

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With my intended use of the M1079 as an offroad camping rig I copied what I did on my previous truck, which also has a parasitic draw... (I added the Bussman Equalizer though)
The 4 battery bank is split into 2+2 separated by a Smart Isolator Disconnect, which is wired for the starter on 2 batteries and the rest of the truck (including the 12v) on the other 2 batteries.
Once the Isolator detects the voltage drop across all 4 batteries below 22.6v (I think), it separates the 2 banks.
Unless there's the highly unlikely draw on the starter end, that bank remains at 22.6v. The other bank could potentially drop to 0v, which kills the cab power.... however, there is a switch on the Isolator which in case of this emergency will temporarily connect both banks and allow the starter circuit to function.
Once running, all the current (the way mine is set up) goes into the main battery bank until it reaches 28v, then the Isolator reconnects and charges the starter bank.
I do have a 24v 60A PV that connects to the Bussman via a Victron controller for when the rig sits outside, and use a pulse charger over winter.
This split system has worked flawlessly for me, and I recently installed one in a class A RV that was having parasitic draw issues.

As a side note, I'm running the 200A 24v alternator conversion kit that I designed, build and sell, as a replacement for the Niehoff. This also allows me to send extra current to the habitat batteries on longer trips.

The Smart Isolator Disconnect is an easy solution.
 

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coachgeo

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......

So you (or someone) are saying that an A1 that has sat with dead or no batteries installed for an extended time has a brick for an ECU as a result? Because that's likely over 90% of the A1's coming out of the various auction houses.
....
dont remember which A1 or A1r.... whichever one or both has a battery in the ecu same as any home computer. There is several threads in here on trucks where they have had to replace the whole ecu cause battery in it was dead/going dead. Other users have pointed that this may be for the very reasons you indicate above as possible causation; while there is other threads that also point out that poor circuit board soldering of the Power Distribution Panel in a few years of the trucks may be part of it too.
 
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