M931 battery wiring

[D6c]

I'd like to wire my M931 to use 2 batteries instead of 4. I have two good batteries and two bad ones and don't want to spend big$ for new ones.

I don't think it will have any trouble with cranking power...I use (2) group 31 batteries to start a D6 dozer without problems.

Anyway, check the attached sketches to make sure I've got the battery cables right.

Thanks

 

[NDT]

Looks fine. I use two of the stud top 31's in my 931 and 915 and they crank the Cummins with no problems. The 6TL's will die on you at the worst possible moment with no warning.

 

[nf6x]

That looks right to me. I think that the only 12V load is the heater blower motor when on low speed.

 

[D6c]

Thanks NDT,
Truck has been sitting since last spring and I need to get it up and going.....Then I'll see if I can get it past the IA DOT's new regristration process.

 

[Castle Bravo]

I want to say the 12v heater connector is a negative lead, but I may be wrong. There are usually 2 more leads as well that are ABS related on most M939 trucks.

 

[D6c]

Quote: "There are usually 2 more leads as well that are ABS related on most M939 trucks. "

I was wondering what the other two wires were for....I'll have to be sure and get them hooked up right too.

 

[D6c]

Installed two batteries this afternoon....test meter showed 24v at starter. Tried cranking, but got nothing but solenoid clicks. Thought I found the problem....had loose wire on solenoid, but it didn't help.

I had the batteries all charged up and cleaned the cables, but I suppose the batteries could be weak.
Next I might trade out the batteries from my D6 since I know they're good.

They didn't do something wierd like wire the truck Pos ground did they?

 

[doghead]

They didn't do something wierd like wire the truck Pos ground did they?

Are you related to Fuzzytoaster?

 

[NDT]

I think you have 4 bad batteries. If they all have the same date, you can count on it.

 

[D6c]

Are you related to Fuzzytoaster?

????

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These two batteries are newer but still could be weak....don't have a load tester handy to check them.

 

[Madclown]

I just replaced two of the 6LT stock NATO batteries with one 8D commercial truck battery. Works great and I installed a keyed Battery cut-off switch while i was at it.