6V Positive ground system

The Cub Club -- Questions and answers to all of your Cub related issues.
Forum rules
Notice: For sale and wanted posts are not allowed in this forum. Please use our free classifieds or one of our site sponsors for your tractor and parts needs.
User avatar
Mrbill
Posts: 11
Joined: Mon Oct 17, 2022 1:22 pm
Zip Code: 46385

6V Positive ground system

Postby Mrbill » Wed Nov 09, 2022 4:43 pm

Question to the group please. I believe I have a 6V positive ground system on a project tractor I picked up (my first :shock: ). It had a newer 6V battery, but I was getting nothing from it. I checked it and it shows 6V after a charge, but it shows -6V. I took it to the auto parts store, and they confirmed. He said the battery was bad. If I hook it direct to the starter, it will turn a couple of times slowly, then stops. So wanting to confirm 6V+ system? Do I need to replace with a specific type of 6V battery? (the one in the tractor had 700 CCA). I have a 12V lying around, can I use that to see if I can get the thing running and/or starter turning? Or will I mess something up? Thank you in advance for your help!
Attachments
t1.jpg
t2.jpg

tst
10+ Years
10+ Years
Posts: 5268
Joined: Tue Jan 12, 2010 2:08 pm
Zip Code: 12514
Circle of Safety: Y

Re: 6V Positive ground system

Postby tst » Wed Nov 09, 2022 7:24 pm

yes that is a 6 volt positive ground, 1 start with making sure all your battery and connections are clean and tight, then if it still has a problem look at the switch on the starter, the contact inside can go bad

User avatar
ricky racer
10+ Years
10+ Years
Posts: 6377
Joined: Wed Sep 12, 2007 8:40 pm
Zip Code: 49120
Circle of Safety: Y
Location: Niles / Buchanan, Michigan

Re: 6V Positive ground system

Postby ricky racer » Wed Nov 09, 2022 7:36 pm

I suggest not using the 12v battery. It will save you from fixing things later. If the battery is truly bad, replace it with a group 1 6v battery. Rural King has the best pricing around here.
1929 Farmall Regular
1935 John Deere B
1937 John Deere A
1941 John Deere H
1952 John Deere B
1953 Farmall Cub

staninlowerAL
10+ Years
10+ Years
Posts: 5030
Joined: Fri Oct 29, 2010 11:34 pm
Zip Code: 36558
Tractors Owned: Cubs: (3)'49's, (1 is for parts), (1)'57 IH Cub LoBoy w/FH, (2)154 Number Series Loboys, (1 is for parts), '76 Longstripe w/FH, Mowers: C-22, Bush Hog 412, Pennington 59, Woods RM42CF, Woods 42, assorted FCub plows, planters, discs, etc. OTHERS: '49 AC B & Ind. Sickle mower, '61 AC D12 Ser 2, '52 8N, '56 Ferguson 35 Deluxe, '47 & '49 Avery V, '53 MM BG (offset), '51 JD M (regular), '56 JD 420C, with Blade and fire plow, '85 JD 850 (Yanmar) w/72" belly mower, '76? Yanmar 2TR15 1500 & Bush Hog SQ42S-2 mower, '78? FORD Dexta, '86 FORD LGT14D & 48" Mower, (2)Cub Cadets & Mowers (MTD), (4) Sears Surburban's, other MTD mowers, Jeeps & other misc. "treasures"
Circle of Safety: Y
Location: AL (Southwest)

Re: 6V Positive ground system

Postby staninlowerAL » Wed Nov 09, 2022 8:35 pm

If the battery tested NG then you need to get a good 6v battery like Ricky said. Once you get that solved and all the connections bright shiny clean and tight (remember that the starter grounds through the frame of the tractor), if the starter turns over slowly (or not at all) get your starter tested. Your starter could be in need of a rebuild. Your coil in the pictures might need a better ground than the strap tied with a piece of wire. JMHO
Stan in LA (lower AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)

Jim Becker
Team Cub
Team Cub
Posts: 17348
Joined: Sun Feb 02, 2003 2:59 pm
Zip Code: 55319
Circle of Safety: Y
Location: MN

Re: 6V Positive ground system

Postby Jim Becker » Wed Nov 09, 2022 9:00 pm

You said the battery shows -6 volts. Are you saying it is charged backwards? If so, that may be why the parts store declared it bad. If that is the case, completely discharge it by hooking a light to it until it is completely dead. Then recharge it the correct way. It may recover. In the other hand, it may not.

halftonstude
5+ Years
5+ Years
Posts: 157
Joined: Sun Sep 30, 2018 3:09 pm
Zip Code: 06482
Circle of Safety: Y

Re: 6V Positive ground system

Postby halftonstude » Sat Nov 12, 2022 9:38 pm

if a battery is reversed long enough to hold a charge in the reverse direction considerable damage has been done to the plates and active material. the plates are generally pure lead or a lead calcium alloy (to make the plates stiffer and stronger) and the chemistry after charging is pretty different: positive grids are lead dioxide and negatives are pure lead. The reversing of the charge will convert much/some of the positive to pure lead and some/much of the negatives to lead dioxide which will cause the plates to change shape and the little pouches of active material (picture the plates looking like a waffle and the active material being the butter smeared into the holes) will not only lose contact with the grids, but some will/may fall out to the bottom and pile up, which is sediment that can foster short circuits between plates later on. reversed cells can recover if they were only reversed for a short amount of time and didn't stay there long. Just in case anybody was wondering... if the red lead of the meter is plugged into the + hole on the meter, and touching the + post of the battery, and if the black lead of the meter is plugged into the - hole on the meter, and touching the - post of the battery, and if the meter shows -6.xx, the battery is reversed. ground connection to the tractor is only a reference and will not influence what the meter indicates - the meter merely reads magnitude. Direction (+ or -) is determined by the location of the leads. Location and placement of the ground cable of the tractor is what determines whether the electrical system is +6v or -6v... or positive or negative ground. Connect the + post of the battery to the frame of the tractor you have positive ground. Ground isn't necessarily earth. The NEC defines ground pretty well: either earth, or a body that serves in place of the earth like the chassis of a vehicle. hope that helps.
c

Eugene
Team Cub Mentor
Team Cub Mentor
Posts: 20451
Joined: Fri Jul 02, 2004 9:52 pm
Zip Code: 65051
Circle of Safety: Y
Location: Mo. Linn

Re: 6V Positive ground system

Postby Eugene » Sat Nov 12, 2022 11:11 pm

12 volt battery will easily power a 6 volt starter without damage and start the tractor. You will need to add a ballist resistor, Chrysler ballist resistor from auto parts store, to the coil for continued operation.

Use the 12 volt battery to conduct compression tests. Ignition off. No need to start the tractor for compression tests.
I have an excuse. CRS.

halftonstude
5+ Years
5+ Years
Posts: 157
Joined: Sun Sep 30, 2018 3:09 pm
Zip Code: 06482
Circle of Safety: Y

Re: 6V Positive ground system

Postby halftonstude » Sun Nov 13, 2022 8:02 am

many old hot rodders keep the 6 volt starters with their flathead engines. gives a great spin for fast starting. the starter is engaged so little there's not really a chance of overheating the windings.


  • Similar Topics
    Replies
    Views
    Last post

Return to “Farmall Cub”

Who is online

Users browsing this forum: Gary Dotson, Ike and 10 guests