8n electrical issue

[blucoondawg]

My friend just bought a 8n, he's not a tractor guy and he didn't inquire with me before he bought he just said look at my new tractor lol, it's a repainted supposedly all gone through mechanically some years back, late model 8n, looks nice, new rubber, runs good, but it's for some issues biggest being electrical. It's still a 6v system and he did buy a brand new battery. However it has a parasitic draw, when running the highest I can get the battery too show is 6.60V, should the voltage read higher than that with the generator supplying power? I was expecting a properly charging system to read more like 7V.

At first it was only reading 6.05 or so, I jumped the field screw on the regulator to ground and it went up to around 8v so we cleaned up the ground to the regulator and the main ground to the frame, now it's up to 6.60V while running. However we shut down for 45 minutes or so and it will drain the battery completely dead, was down to 1.3V after sitting 45 minutes.

We have not replaced the voltage regulator yet, have one on order, is this large parasitic drain something that a bad voltage regulator could cause on a 6V positive ground system? Any opinions on other sources, could a bad generator be draining the battery down? I'm not familiar much with the Ford or the 6v and he has absolutely zero tractor knowledge.

When he went to buy it the old guy had a charger on it to start it, he lied and said he left the key on, that's when I would have got in my truck and left, but he didn't and now he over paid for some problems I'm trying to help him square away.

 

[i7win7]

Saw a generator actually run on a IH model M that was shut off. Think it was regulator issue. Grandfather disconnected battery, fixed it later.

 

[blucoondawg]

That is one huge almost unbelievable drain. It should be easy as pie to find, probably just by feeling for warm wires. If the battery is getting drained that much, the generator hasn't got enough current capacity to get the battery up to normal charging voltage until several hours have passed. Chances are the charging system is OK. Unless there are a lot of accessories hooked up, I'd look in the direction of the starter first after you disconnect the VR to see if that is causing a drain.

Saw a generator actually run on a IH model M that was shut off. Think it was regulator issue. Grandfather disconnected battery, fixed it later.

That is what I was wondering if that could be the case, though it's not turning but I thought I read somewhere you could jump certain wires and make the generator turn as a test to see if power can pass through the generator

 

[John0829]

It is likely the points in the VR are burned and sticking, try removing the battery wire from the VR and see if the vampire drain stops.

 

[blucoondawg]

It is likely the points in the VR are burned and sticking, try removing the battery wire from the VR and see if the vampire drain stops.

I see there are 2 wires hooked to that battery connection on the vr, is that normal or maybe they have some screwy wiring going on? Maybe they tapped power off there for something

 

[blucoondawg]

Here is a diagram for a late 8N. The early front mount version is almost the same.
View attachment 693815

Thanks I will look it over today when I go back over there, what is the colored in rectangle symbol below the ignition switch depicting?

 

[LD1]

Thanks I will look it over today when I go back over there, what is the colored in rectangle symbol below the ignition switch depicting?

That is usually a resister.

The only thing the ignition switch kills on an 8n is the ignition coil. Nothing else. (Unless a bunch of accessories were added like lights). So whatever is draining the battery.....is also draining it while running. And actually.....if your battery is completely dead and less than 2v in 45 minutes.......that amount of drain would even exceed the generator output. I'd guess you can run the tractor ALL DAY.....and at the end of the day you wouldnt be able to restart as the battery would be dead.

A DC amp clamp would be a good start here. (or a meter capable of checking inline amps but those are usually limited to 20A).

Start unhooking things. See if the ampmeter works too. Because any drain should show up unless its at the starter. Because everything else goes through that meter (or should)

 

[RickB]

Thanks I will look it over today when I go back over there, what is the colored in rectangle symbol below the ignition switch depicting?

A junction block. This system has no resistor, a front mount distributor N will have a resistor.

 

[blucoondawg]

Ok so a little progress, I had my buddy go out there last night and unhook the battery terminals from the voltage regulator as suggested above. There are 2 wires on that terminal rather than one so I have to get over there to look at that and see what's going on, however with they terminal disconnected he took a reading of 6.57V and went to bed, this morning he still had 6.29V so that did eliminate the biggest part of the issue. Hopefully it is just stuck points in the regulator and they will fix it. New regulator is coming from Amazon tomorrow

 

[blucoondawg]

That is usually a resister.

The only thing the ignition switch kills on an 8n is the ignition coil. Nothing else. (Unless a bunch of accessories were added like lights). So whatever is draining the battery.....is also draining it while running. And actually.....if your battery is completely dead and less than 2v in 45 minutes.......that amount of drain would even exceed the generator output. I'd guess you can run the tractor ALL DAY.....and at the end of the day you wouldnt be able to restart as the battery would be dead.

A DC amp clamp would be a good start here. (or a meter capable of checking inline amps but those are usually limited to 20A).

Start unhooking things. See if the ampmeter works too. Because any drain should show up unless its at the starter. Because everything else goes through that meter (or should)

Correct running the tractor doesn't give enough charge, I can charge it with a 10 amp better charger and it will turn over like a million bucks, run it for 20 minutes and go to start again and I can probably get one more start out of it but it's very slow cranking. After that it will need the charger put on it if you need to start it again.

It does have headlights and a treat I work light but that is the only electrical thing on it besides the starter and charging and ignition system