6volt / 12 volt Ford 8N Tractor. From 1947

[knuckle47]

Short but long story short. I have no clue who did what to this 78 year old tractor other than I bought it 3 years ago. EVERYTHING on it screams it is a 6 volt tractor, positive ground. The more recent method of 12 volt conversions usually has a modern alternator sticking out of the side of the engine and is very obvious

The battery that was in it when I got it as finally crapped out so I would not crank fast enough to start. I bought a new 6v battery but when installed, it barely cranks over very slowly…I took a 12 volt jump pack and connected it to the battery cables and she cranked quickly and started right up. While running I disconnected the jump pack just in case and it ran well.

I am getting a 9 to 15 volt reading on the voltmeter. I returned the old battery as part of a core exchange so I don’t know if it was really a 12v battery.

Could someone have used some 1950’s or 60’s generator or other parts and converted this thing decades ago? Could a 6 volt generator produce 9 to 15 volts? Could this coil and resistor start the engine and remain connected to 12 volts?

Any thoughts … frankly, it started so well I was tempted to just toss in a 12 volt battery and call it a day

 

[fantic]

The generator should be able to produce that much voltage. Maybe someone replaced the voltage regulator with a 12v one. I would look on the firewall of the tractor and look for a 2" X 3" black box with wires coming in and out of both sides. It should say on the top the voltage. I converted my Ferguson 30 to 12v. I just used the alternator from an old small block Chevy. Well worth it in regards to cranking.

 

[Waorani]

Do you remember if old battery posts were on same or opposite sides? If same likely 12V, opposite likely 6V. Also make sure new battery has full charge.

 

[knuckle47]

@Waorani …good point…they are on opposites sides for the old and the new battery… the new battery was on a 5amp NOCO maintainer for 24 hours before I added it but cranked like it was only using 2 cells. I was a bit surprised but that’s when , out of frustration, I used the 12v jump pack. When it actually sounded healthy when cranking over, that 12v conversion was a real thought.

My 56 ford generator looks very similar to the tractor generator and this tractor has some very cool home made modifications …so I was wondering if this 1960’s parts swap might have been a thing.

If it is really just stock…then I’m surprised I’m getting 14-15 volts out of the generator

 

[Waorani]

Could be a bad battery. It happens. I just got one of the NOCO 5amp chargers but haven't used it enough to know if it would give you a fault or not. Did it go green in 6V mode? Also have one of the 1amp NOCOs and it took a couple days each to bring two different 6v batteries up to full charge. And those batteries were still cranking. I think a 6V generator could be putting out that much if running through a 12V regulator. You might have a mixture of parts on a machine that old.

Old timer neighbor always tells me to stick a 12v on various 6v motors I mess with saying it won't hurt anything but I figure if they'll crank on 6v why risk problems.

 

[knuckle47]

Thanks…l I agree with you. I have several of those NOCO 5A units running at 12v but this 6v one I always kept on the tractor. I think….given the pain the the butt it is getting under the hood, I’ll just pull it off and complete the 12V conversion. I will say, the cranking ability of the starter has never been like that and this motor started instantly. That was impressive particularly that I had rebuilt the carb last year and never really had the chance to see it’s starting ability since this battery has been going bad the last 10 months or so and usually pulled out the can of ether

She’s an old one BUT does the job for me…if it could only dig, I’d be all set

 

[knuckle47]

Update: Returned the new 6v battery for another 6v…installed it with the cranking speed about 1/2 of the 12v… thing is, it starts up and runs

 

[knuckle47]

Due to the 1/4” size increase on all battery dimensions, the entire hood had to be lifted. Gas tank is bolted to the hood so it had to be drained as well..the hydraulic pump for the front loader is driven off the engine pulley directly. Those bolts left and right took an hour to get lined up for assembly. I can’t lift stuff like this any more so a drift helped very little getting it in position … here’s a few more pictures…remember it is 78 yrs old and never re-painted.

The tubing framework for the bucket is the reservoir for the hydraulic fluid … probably 6-7 gallons within the 2” tubing