M1078a1 battery connection diagram help

[jmenende]

Howdy folks. Im getting ready to fire up my first m1078a1 but can seem to get the battery wiring right. My battery cover with a diagram is missing and some of the cables were missing too. Manuals for the a1 are not available and my unit has a battrry disconnect not shown in the diagrams of tha Ao. Could someone please post a clear picture of the wiring sequence on a A1.

 

[swiss]

Are you going to run 2 or 4 batteries?

 

[jmenende]

Are you going to run 2 or 4 batteries?

I want to run 4 batteries. I have already bought the 6tl's. Id like to keep everythinh as stock as possible.

 

[Ronmar]

The A1 and A1R are wired the same. You can find an A1 schematic in the manuals section here on SS.

in the end pretty basic:
2 grounds a 12 and a 24 cable…

One ground goes to the starter neg terminal(front of starter case).

A second ground goes to the slave-jumpstart connector.

One 12V goes to the 12V terminal on the manual disconnect. That 12V cable end on the disconnect should be labeled TL12B

One 24V goes to the 24V terminal on the manual disconnect. That 24V cable end on the disconnect sw is probably labeled TL12A



You only need 2 batts which will simplify your wiring and ease the stress on the alternator.

 

[jmenende]

ok. Let me study the diagram and ill report back. Thanks again.

 

[coachgeo]

where I found it confusing is the actual wiring on my two trucks (A0's), on one of them at least it has more cables than diagrams show. Others have said it is likely for easy way to compensate for where higher gauge needed in a few spots... so instead of some heavier than other gauge here and there... they added another cable in different location that essentially does same as a sister cable.. but now divides the job between two cables.

 

[jmenende]

where I found it confusing is the actual wiring on my two trucks (A0's), on one of them at least it has more cables than diagrams show. Others have said it is likely for easy way to compensate for where higher gauge needed in a few spots... so instead of some heavier than other gauge here and there... they added another cable in different location that essentially does same as a sister cable.. but now divides the job between two cables.

Eaxtly. I have a long cable coming from the cabin side and 3 cables coming in from the disconnect box. I have seen plenty of vides and dont see what i have. Mine came without the cover so no diagram and i believe it was missing 2 of the positive to negative cables. I managed to get 12v and the lights in the cab turn on but cant get the 24v for the starter to crank. Im going to post a pic of my connection layout.

 

[Ronmar]

The A1 moved some connections used in the A0 from the battery box to the A1 switch box.

The single wire toward the cab is probably the main ground to the starter. The 3 wires to the switch box are probably ground for the slave connections and 12 and 24 to the manual disconnect.

 

[jmenende]

The A1 moved some connections used in the A0 from the battery box to the A1 switch box.

The single wire toward the cab is probably the main ground to the starter. The 3 wires to the switch box are probably ground for the slave connections and 12 and 24 to the manual disconnect.

 

[jmenende]

The A1 moved some connections used in the A0 from the battery box to the A1 switch box.

The single wire toward the cab is probably the main ground to the starter. The 3 wires to the switch box are probably ground for the slave connections and 12 and 24 to the manual disconnect.

Yes, the only long cable that comes from under the cab is the ground.

 

[jmenende]

Ok. I think i got the wiring right. The slave port now shows 24v. The generator has two alternating yellow lights. I have to wires in the pic below that i dont know where they go. The one with the terminal has 17vdc. Weird.

 

[TomTime]

Ok. I think i got the wiring right. The slave port now shows 24v. The generator has two alternating yellow lights. I have to wires in the pic below that i dont know where they go. The one with the terminal has 17vdc. Weird.

I don’t know where the white wire goes but on my truck the black wire goes to the negative post on the front left side battery.
See picture of my batteries.
The generator should show two green lights when operating correctly
That’s the best I can do for you.
Good luck .
Tom

 

[jmenende]

I don’t know where the white wire goes but on my truck the black wire goes to the negative post on the front left side battery.
See picture of my batteries.
The generator should show two green lights when operating correctly
That’s the best I can do for you.
Good luck .
Tom

Thanks for the pic. It helps alot. I see a connection that i dont have. Does the back cable that connects both positives then connects to the front right positive post ? Like in this pic

 

[TomTime]

Thanks for the pic. It helps alot. I see a connection that i dont have. Does the back cable that connects both positives then connects to the front right positive post ? Like in this pic

No. That wire from the back right side battery goes down between the two right side batteries and out to the battery cut off switch. It does not connect to the front right side battery.
But there was a battery tester that came with these trucks and mine was toast. The white wire may have went to the battery tester.
Hope that helps.
Tom.

 

[jmenende]

No. That wire from the back right side battery goes down between the two right side batteries and out to the battery cut off switch. It does not connect to the front right side battery.
By they was a battery test that came with these and mine was toast. The white wire may have went to the battery tester.
Hope that helps.
Tom.

Is the wire that connects to the front left negative post number# 1650?
I have another thats #1651, and dont know where it goes.

 

[TomTime]

Just as a follow up to the battery tester I mentioned. If you look at my picture, the center divider between the left and right side batteries that silver clip in the middle of that divider is what held the battery tester when not in use. As I said, my was bad so I eliminate it.

In reference to your last question, sorry I can’t help out right now because I’m not home at this time. I had the picture I posted on my cellphone. When I get home I can look for you or maybe someone else can get you the answer before me.

Tom.

 

[Third From Texas]

where I found it confusing is the actual wiring on my two trucks (A0's), on one of them at least it has more cables than diagrams show. Others have said it is likely for easy way to compensate for where higher gauge needed in a few spots... so instead of some heavier than other gauge here and there... they added another cable in different location that essentially does same as a sister cable.. but now divides the job between two cables.

On A0 trucks it's not uncommon to have 2x 24v leads at the inboard left. If I recall, one goes to the starter and the other to the polarity protection box. They connect to the same terminal, and are often depicted as one cable in a lot of the diagrams. My A1R only has the one 24v cable in that location.

 

[Ronmar]

On A0 trucks it's not uncommon to have 2x 24v leads at the inboard left. If I recall, one goes to the starter and the other to the polarity protection box. They connect to the same terminal, and are often depicted as one cable in a lot of the diagrams. My A1R only has the one 24v cable in that location.

Dont forget the slave receptical…

They branched the 28V line to the slave receptical off of the disconnect sw and they split the output of the disconnect relay 28 to the starter and LBCD. On the A0 all 3 of those lines run to battery +28V…. My A0 had 6 leads total into the battery box.

I have it down to 3 leads now, connecting to a pair of group 31’s…