Trying to figure out the general layout of the m1070s electrical system.

[Hawssie]

I am still trying to get a hold of a wiring diagram for the M1070 that I can actually read, and one I could print and read afterward would even be better. I had posted earlier that my M1070 doesn't have a battery disconnect, and as I am getting ready to do that, I first had a few questions. It appears that a lot of the truck's system at least most of the typical acc. stuff is 12 volt. I know it has 2 alternators one 12v and one 24v. (I also noticed the A1 has 2 24v alts instead but thats another topic). My question is how does the M1070 go about delivering and providing for the 12V and the 24V systems. The 24v seems straight forward but how does the 12v do its stuff? Does the alternator charge just one of the batteries? That doesn't seem right. It must not have an inverter or why would it need a 12v alternator. I remember Dieselfreak saying how overseas he used the in cab 24v acc plug for 12v ( for small fridge etc.) by using an inverter, but why would you need that when you already have 12 volt. That makes me think the 12V part is limited in amperage. And when I disconnect the batteries will disconnecting the 24V leads take care of isolating 12v part as well? I am sure you guys can demystify this for me!

 

[ke5eua]

The battery disconnect is on the 12v side.

Most of the electronics in the truck are 12v, and yes the 12v alternator just charges the 2 batteries while the 24v one charges the 24v side.

When you have a lot of stuff that pulls on the 12v side the batteries become unbalanced. You can solve this by using an equalizer or a small alternator.

As far as printing the schematic you could the PDF to a place that has a plotter and ask them to print that page on the plotter.

Other option would be printing as a poster.

 

[HETvet]

The reason I said to use the 24 volt source is because is an actual plug. To tap in to the 12 volt side would mean hot wiring in to something. It also is a kill able source. Meaning that if the ignition switch is in the off position, then there is no power going to that plug. So when your bedding down and watching a movie, you would have to shut the switch off; most of the time the truck was idling. Any other source you could have every thing off, fall asleep and wake up to a dead truck.

 

[Hawssie]

Thanks for the clarification on the 24v plug. So if the 12V alt charges 2 batteries(not one) then it must charge one of the batteries on each side of the pairs that are wired in series. I have some nice 100 amp Cooper Bussman inverters but I was thinking I didnt need one for this application but maybe I do. I am now thinking how an inverter would be used. I guess you would end up with two different 12v sources? The original that draws off of 2 batteries that are charged by the 12v alternator and then the inverter one which would draw off of all 4 and is charged by the 24v alternator. Seems like it would be better if you are going to run 2 alternators, make them both 24v then just run an inverter for your complete 12v source. I do need to do something about the diagrams, as I have downloaded the appropriate TMS but when I open the diagrams I cant read them, and I cant seem to print them either. If anyone knows where I could buy a foldout that would be great also.

 

[Hawssie]

Actually I went back and read the info that came with my inverters and at the same time I was thinking about how you mentioned to use an equalizer. I never paid much attention to the difference between an equalizer and an inverter, but now I see how by wiring the "inverter" slightly different it becomes an equalizer which I think I can tie into the existing 12v source, so the 12v will all be from the same system.

 

[ke5eua]

Actually I went back and read the info that came with my inverters and at the same time I was thinking about how you mentioned to use an equalizer. I never paid much attention to the difference between an equalizer and an inverter, but now I see how by wiring the "inverter" slightly different it becomes an equalizer which I think I can tie into the existing 12v source, so the 12v will all be from the same system.

Inverter and equalizer are two completely different things.


An equalizer is used to balance the battery system when the 12v side is being discharged at a greater rate than the 24v side and it charges the 12v side to keep them balanced.

An inverter takes a voltage, increases it or decreases it and changes it from dc to ac.

The inverter was used to provide house electric power to run a mini fridge and a laptop while on mission.

As far as the batteries, there are 4, wired in a series parallel configuration. So it charges the last two batteries in the series for 12v, right side. Wire with the blue heat shrink is the 12v main. The cross over is the 12v source and the side with the main ground is the 12v side, if that makes sense.

Unless you plan on running an excessive amount on the 12v side you do not need an equalizer. Remember this truck has two alternators, one for the 24 and one for the 12 so an equalizer isn't needed.