7700 turbo

dmiller · Oct 9, 2013

Have an opportunity at a 7700 Turbo Deere. The current owner told me the batteries were bad, that they were 2 6 volt in series and to bring a battery. I went with a good 12 volt (out of my grain truck), could barely spin the motor over.
Took the batteries that were in it home with me, checked them with a volt meter and found out they are 12 volt (one showed 10.7 volts, one showed 11.2)
Was this a 24 volt system???

DeltaRed · Oct 10, 2013

Look at how the batterys were hooked up.Parelel it is 12 volt.Series is 24 volt.My guess is 24 volts to start,then the voltage is reduced to 12 volt for everything else.Just like the 4010 and early 4020.

coonie minnie · Oct 10, 2013

I seriously doubt your combine is 24 volt. Usually Deere uses to 12 volt batteries in parallel on combines. My old 105 diesel has two 12 volts- they are hooked in parallel.

The 7700 being newer would not have gone backwards to 24 volt.

Anonymous-0 · Oct 10, 2013

if the batteries have a common ground and both positive terminals go to the starter it is parralel, if the positive of one batt. goes to the neg. of the other then it is series, my guess is the former, hopefully it doesn't have a cluster #$%^ electrical system like a 4020

Anonymous-0 · Oct 10, 2013

I wouldn't think it would as a 7700 turbo was made way after jd abandoned that dumb a$$ system, the electrical systems on all of the tractors we have owned worked just fine without a split load system

Nathaniel Watts · Oct 10, 2013

The only people who bash the 24 volt are the ones who don't understand it. If you keep clean battery connections, it gives just as good of service as anything else.

dmiller · Oct 10, 2013

You guys answered my real questions, There are 2 12 volt batteries (I was expecting 2 6volts to make a 12 volt system) I assumed it was wired series like on the older tractors (my 806IH is that way).
I'll have to look at the way the lines go when I put it back together, thinking back it probably was wired parallel not series based on how long the ground wire between batteries was and where it would have to go for it to be wired series.

Anonymous-0 · Oct 10, 2013

why do you need it? everything else started and worked without it IH, Oliver, Case ect., are you another one of those jd's perfect people?

johndeere720diesel · Oct 10, 2013

I have a 4400 and starts just fine with one good size 12volt it's a group 65. You may have a starter issue. Or battery cable issues

randy hall · Oct 10, 2013

twelve volt system. I use one gell cell battery and it will crank as fast and as long as two regular twelve volt batteries.

Nathaniel Watts · Oct 11, 2013

Nope, I own all kinds. I have a 730 diesel that cranks when nothing else will. It may not me what everyone is used to, but it is a good system and worked a long time. You just can't butcher the wiring and have poor connections.

Dalet · Oct 13, 2013

2 6V's in series is what my 7700 needed to fire off. Same for the 4430. You have to switch the wiring if you are using 2 12v batteries.

7700 turbo

dmiller

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DeltaRed

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Anonymous-0

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Anonymous-0

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