3020 Backwards Battery Wiring

[Jeepinnc]

Ive got a 3020 24v diesel (bought from an old farmer that liked to rig things) that the battery wiring is exactly backwards from the factory diagram. On my tractor the cable from the starter goes to the negative post on the right battery rather than the positive post as in the diagram. The rest of the wiring is backwards from the diagram as well. Now the tractor cranks and runs just fine.

My question is why would someone have reversed the wiring like this?
Also, will it present a problem if I ever have to replace the starter, solenoid or some other electrical part?

 

[wore out]

Lots of those 24 Volt systems have gotten "confused" when someone replaced the batteries and didn't pay attention.

As long as the generator gets polarized to match the battery configuration without causing the cutout contacts in the VR to stick all will be well, and it really doesn't make much difference, about the only thing you'd notice is that the fuel gauge (IF in working condition) may not be accurate.

The starter and solenoid and for the most part the voltage regulator are NOT affected by polarity, although if the VR is of the type that uses different metals in it's upper and lower contact points it's life may be shortened.

The GENERATOR is the polarity-sensitive component and needs to be polarized BEFORE startup IF you decide to reconnect the batteries as they were when the tractor left the factory OR you replace the generator.

 

[matthies]

Went and looked at a 3010 last year, kid said it starts the same as it did with the old batteries(and charger). Farm store gave his mom two 6 volt batteries instead of two 12 volt batteries. Never heard from
him again. 24 volt system. He tried to pay me for my trip, couldn't take anything, they lost their husband/father years earlier from cancer and I wanted to help out.

 

[Jeepinnc]

(quoted from post at 08:25:09 10/28/20) Lots of those 24 Volt systems have gotten "confused" when someone replaced the batteries and didn't pay attention.

As long as the generator gets polarized to match the battery configuration without causing the cutout contacts in the VR to stick all will be well, and it really doesn't make much difference, about the only thing you'd notice is that the fuel gauge (IF in working condition) may not be accurate.

The starter and solenoid and for the most part the voltage regulator are NOT affected by polarity, although if the VR is of the type that uses different metals in it's upper and lower contact points it's life may be shortened.

The GENERATOR is the polarity-sensitive component and needs to be polarized BEFORE startup IF you decide to reconnect the batteries as they were when the tractor left the factory OR you replace the generator.

I should have mentioned it has an alternator instead of generator. Not sure if that matters.

Any reason not to switch it back to the factory set up?

 

[John T]

Jeep if it has an Alternator its been EITHER converted to 12 Volts and likely NEGATIVE Ground orrrrrrrrrrrr if as it was original and still 24 volts it would need to be a two wire isolated from frame 24 Volt Alternator !!!!!!!!!!!!!!!

I wonder if its been converted to 12 Volts ?????????????? and Negative Ground. Does it have two 12 volt batteries ?? and are they connected in series (24 Volts) or parallel (12 Volts) ??

John T

 

[Jeepinnc]

It is 24v and it has an alternator. I tried to post a picture but the site says its spam and wont let me.

 

[Tx Jim]

Ditto what John T stated. Positive ground & alternator don't normally go together. Go down to site comments on home page & ask permission to post photos

 

[Jeepinnc]

When allowed, I can post pictures . But I know for a fact its a 24 volt, 2 batteries in series. Its just backwards.

Is returning it back to factory spec in regards to polarity going to be ok?

 

[tomstractorsandtoys]

I am not very good at wiring but I think some of the 5010-5020 tractors used a 24 volt alternator. I could be wrong. Tom

 

[wore out]

"I should have mentioned it has an alternator instead of generator."

Is it an "isolated ground" Motorola alternator as was used with air conditioned tractors, or has someone "reinvented the wheel" and installed some other 24 Volt alternator that is not an isolated ground unit and mucked up the wiring accordingly?

 

[Jeepinnc]

(quoted from post at 20:40:33 10/28/20)
"I should have mentioned it has an alternator instead of generator."

Is it an "isolated ground" Motorola alternator as was used with air conditioned tractors, or has someone "reinvented the wheel" and installed some other 24 Volt alternator that is not an isolated ground unit and mucked up the wiring accordingly?

The latter is what I believe to be true. Its a Delco Remy 24v alternator. Im going to take a few pictures and post them so everyone is on the same page.

 

[Tx Jim]

4020 below serial # 201000 with factory cab could be equipped with a 24 volt alt but IIRC these were Motorola alternators

 

[John T]

To take it back to the original two wire 24 volt system where the (then) Generator was isolated off frame, the 24 volt Alternator must be a two wire likewise frame isolated unit. Once that's established so long as its polarity is the same as the batteries it can work and if NOT the alternator may already be fried. If its working properly I hesitate to change any polarity.

John T

 

[Jeepinnc]

Alright guys, after taking some pictures, Im not sure what is going on here. Below is what I have:

Here is the factory diagram:

First off here is the RIGHT side battery, take note of the red battery cable. This goes to the starter and should be hooked to positive terminal but here its on negative terminal:

However, instead of going straight to the starter it makes a stop here to a bolt in front of the LEFT battery under the platform (like its establishing a chassis ground) then proceeds on to the starter:

The black cable from the RIGHT battery is going from positive to the negative terminal on the LEFT battery. The positive terminal on the LEFT battery goes to the solenoid.

 

[Jeepinnc]

Here are the pics of the alternator:

 

[John T]

That doesn't look like a frame ground isolated alternator to me (more like a delco 3 wire???) BUT I CANT SAY FROM HERE FOR SURE.

John T

 

[John T]

A few observations:


1) The starter will still turn the same direction AT EITHER POLARITY, so even if backwards its okay.

2) So long as the alternator is connected at the correct polarity it can still charge the batteries (provided its the correct voltage and
matches polarity) even if they are not same as original

3) If two 12 volt batteries are still connected in series and the center mid tie point is bonded to frame ground THATS SIMILAR TO HOW THE
ORIGINAL 12/24 VOLT SYSTEM WORKED. One battery feeds 1/2 of the 12 volt - ground loads other battery feeds other 1/2 of the 12 volt +
ground loads

HOWEVER the alternator doesn't look like a frame isolated alternator (such would have two output studs + and -) it looks like a Delco
three wire unit with the case serving as one conductor (typically -) and the big stud the other (typically +)

John T

 

[John T PS]

Im unsure just how that alternator charges BOTH batteries ????????? If it has one perhaps + output stud and the other perhaps - termination
is its case frame, how would it charge BOTH batteries in series??? I can see it charging one or the other BUT EVEN WITH THE PICS NOT BEING
THERE I JUST CANT SAY......

Sorry I cant answer your questions

John T

 

[Tx Jim]

(quoted from post at 15:57:26 10/29/20) That doesn't look like a frame ground isolated alternator to me (more like a delco 3 wire???) BUT I CANT SAY FROM HERE FOR SURE.

John T

I agree it appears to me with the alternator in photo only having 1 large battery post that it must utilize alternator frame as a ground connection which will not operate correctly on an original JD 24 volt electrical system.

 

[Jeepinnc]

(quoted from post at 15:27:43 10/29/20)

(quoted from post at 15:57:26 10/29/20) That doesn't look like a frame ground isolated alternator to me (more like a delco 3 wire???) BUT I CANT SAY FROM HERE FOR SURE.

John T

I agree it appears to me with the alternator in photo only having 1 large battery post that it must utilize alternator frame as a ground connection which will not operate correctly on an original JD 24 volt electrical system.

Copy. So its in you twos opinion that the way this tractor is currently wired its not performing as it should?

Is converting to 12v the best solution or something else?

 

[J.Wondergem]

Does this tractor have a parallel switch? Are the light bulbs 12 volt?
I had Mack road tractor years ago is why I ask.

 

[Tx Jim]

Copy. So its in you twos opinion that the way this tractor is currently wired its not performing as it should?

Is converting to 12v the best solution or something else?[/quote]

IMHO if your tractor isn't a collector "show queen" then changing electrical system to 12 volts is the best thing to do. You'll have more hair with darker color utilizing a 12 volt system. Newer type 12 volt starters are much more powerful than 12 volt starters built back in the 60's.

 

[John T]

Yo Jim, you state "I agree it appears to me with the alternator in photo only having 1 large battery post that it must utilize alternator
frame as a ground connection which will not operate correctly on an original JD 24 volt electrical system."

hey that makes two of us on the same page

John T

 

[John T]

If its working fine as is and charging BOTH batteries ??? fine but if NOT Id at least consider converting to 12 volts

John T

 

[Tx Jim]

hey that makes two of us on the same page

John T[/quote]
John
Even a blind hog can locate an acorn sometimes ! !!! LOL

Due to the fact your email box is closed would you please email me. I thought I had your email address but I guess not so.
Thanks, Jim

 

[Jeepinnc]

(quoted from post at 03:36:07 10/30/20) Copy. So its in you twos opinion that the way this tractor is currently wired its not performing as it should?

Is converting to 12v the best solution or something else?

IMHO if your tractor isn't a collector "show queen" then changing electrical system to 12 volts is the best thing to do. You'll have more hair with darker color utilizing a 12 volt system. Newer type 12 volt starters are much more powerful than 12 volt starters built back in the 60's.[/quote]

Unfortunately, the more hair ship sailed a few years ago. A follow up question, is it normal in the 24v system for the battery cable to stop at that bolt in my picture before proceeding on to the starter? Factory diagram doesnt show that.

 

[John T]

In the original it was only a smaller mid tie point frame ground jumper wire NOT a big battery cable that bonded to the tractors frame.
Pretty sure of that, see if Tx Jim agrees????

John T

 

[Tx Jim]

is it normal in the 24v system for the battery cable to stop at that bolt in my picture before proceeding on to the starter? Factory diagram
doesnt show that.[/quote]ttps://www.yesterdaystractors.com/cvphotos/cvphoto61144.png[/img]

 

[Tx Jim]

Yes sir I agree with you.

 

[SVcummins]

I ran a 12 volr alternator on my 24 volt system for a long time
hooked the alternator output to the post on the battery that
showed 12 volts positive and it was worked how or why I don’t
know

 

[Tx Jim]

I'd have to witness a 12 volt alternator charging on a JD 24 volt system & had not sent out a smoke signal. I've read where miracles do happen & 12 volt alt operating on JD 24 volt system would definitely be classified as a MIRACLE in my mind!!

 

[SVcummins]

Well i ran it that way from 2007 until 2017 so I don’t know
what to tell you i do know if you don’t use a meter to find the
12 volt postive voltage you’ll fry the alternator in about 3
seconds

 

[SVcummins]

Yes go to 12 volts if you’re having wiring or starting charging
issues . You can buy a delco 10 si for about 90$ and a gear
reduction starter for a couple hundred or less then new
battery cables you can do it for about 3 or 400$

 

[SVcummins]

12 volt alternator charging a 24 volt system

 

[Tx Jim]

Sorry but IMHO all your photos prove is your tractor has an alternator but not how batteries or alternator are attached to electrical system(12 or 24 volts)?

 

[SVcummins]

Thats all the photos i have I don’t have anything to prove but i
ran a 12 volt alternator on a 24 volt system for quite awhile
why or how it worked I don’t know but it sure beat only being
able to farm for a few hours at night before the batteries went
dead the having to put the charger on over night. If i had
known how easy it was to convert to 12 volts i would have
done that to start with

 

[Tx Jim]

If I'm understanding you correctly with batteries attached in 24 volt configuration & 12 volt alternator attached to 1 battery you could operate tractor at night with headlamps operating then the next day engine would start with no charging/boosting of either/both batteries. Correct????