8N 6 Volt Not Charging

   / 8N 6 Volt Not Charging #1  

spotco2

New member
Joined
Dec 11, 2012
Messages
23
Location
Ga
Tractor
Ford 8N
Well, I went out to play with the old tractor a little the other day and it fired right up after I charged the battery.

It ran well for a few hours then I started having to keep it idled up to run. After a few hours of playing I shut it down and it would not spin over to start back up. After a little sitting, it cranked and continued to run poorly. I finally parked it (getting dark) and went out yesterday to play some more. Ran fine for a while and then started having to idle it up. Same thing today and for giggles I checked the battery voltage and the darn thing don't seem to be charging. Apparently I have just been running off battery power for 3 days :(

So I break out the books and meter and I definitely ain't charging. One thing I thought was odd was I got a spark at the battery cable when I put the negative back on today. Yes this still has positive ground.

I know that I can ground the field and apply 6 volts to the arm to make it tun as a motor to check the generator. Most I've seen had a F and A stamped in the case but I can not find it on this one. Which is which?

As it sits now, the generator is on the opposite side of the engine than the starter. The wire on the top post closest to the engine is actually UNDER the post grounding itself out and the nuts on the post are seized by years of rust. The wire next to it appears to be ok and the wire on the back appears to be ok. If I attach my meter to ground I do not get any voltage at any of these wires. There is continuity on each of these wires with the other end at the regulator. If I attach my meter to the battery with the tractor running, I only read battery voltage (6.2v-6.4v ish).

I've got a new wire harness but have not installed it. My tractor was rewired at some point since 1949 and I'm having issues figuring out which end of the new harness goes towards the front of the tractor. It does not appear to even be close to what I currently have. I also do not currently have an ammeter installed on my tractor.

Anyways, what's a good start to troubleshooting my generator not generating issues? Pics would be more than helpful.
 
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   / 8N 6 Volt Not Charging #2  
same thing I told you on ytmag.

if you see a spark when pulling a bat cable and key is off.. you need to trace wireing.

also.. if gen motors fine.. check reg.

armature is big stud on back of genny.. field and ground are on BB of gen.. field is insulated with a phenolic washer or rubber grommet

if gen will motor but not charge.. start up and ground field. if it charges.. field ckt is bad.. repalce reg...if no charge.. jump bat to arm.. if it charges.. cutout is bad... replace reg.. etc..
 
   / 8N 6 Volt Not Charging
  • Thread Starter
#3  
Yeah, I've gotta figure out what caused that spark when I connected the battery cable. It can't be much.

I jumped the BAT and ARM on the regulator for a second or two and also ran a jumper from the negative of the battery to the armature of the generator for a couple of seconds.

Fired it up and put the meter on the battery. It bounced around from 6.3v-7.2v, so I reckon I'm generating.

Tractor ran much better today for about 6 hours. We will be busy all day tomorrow, so I'll play with that new wire harness later in the week.

Only problem today was the left side of the scrape blade kept jumping out of the quick connect on the 3 point hitch. Always the left side and happened multiple times for some reason. I've ran that same blade several times before without any problems. Sounds like another project for me.

Thanks .
 
   / 8N 6 Volt Not Charging #4  
Yeah, I've gotta figure out what caused that spark when I connected the battery cable. It can't be much.


put a test lamp inline with hot cable.. now work from the far end of the wire harness and break connections till you find one that makes the lamp go out. when you do.. that connection is feeding the short circuit.

I jumped the BAT and ARM on the regulator for a second or two and also ran a jumper from the negative of the battery to the armature of the generator for a couple of seconds.

redundant but won't hurt. bat on reg = bat hot / neg on a + grnd system.

Fired it up and put the meter on the battery. It bounced around from 6.3v-7.2v, so I reckon I'm generating.

bounce may be loose brushes.. or tall mica or rouch comutator.. or simply low quality consumer grade meter.. either way.. sounds ok for now.
 
 
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