6v Charging Systems and Positive Ground (questions, questions)

[GJS]

Alright, I'm going to be OOZING ignorance in this post as it is on my weakest topic: electronics.

I've got an old Economy Country Squire tractor that I've been picking away at since 2012 and I'm finally gettining down to putting the electrical system into it. It's a 6v system with a geared starter (Auto-lite MAK 4008 which I've been running for about a year, hooked up negative ground) and a Generator (Delco-Remy 1100036 which was rebuilt). The generator basically charges the battery and runs only three lights.

The hang up is polarity. Any documentation that I can find (bascially the original Wisconsin AENL service bulliten) is that the "system" is positive ground. The physical wiring for either option is clear to me so my questions are:

1.) How can I tell if the Gen is negative or positive ground?

2.) Assuming the Gen IS positive ground, does the battery (which has been charged as standard neg-neg, pos-pos) need to be completely discharged and recharged as positive ground (neg-pos, pos-neg) in order to safely recieve charge from a positive grounded Gen?

I'm likely making a way bigger issue of this than need be but stuff like batteries blowing up and whatever never really appealed to me.

Any help would be appreciated. Thanks!

 

[Big_John]

#1 I think the generator can run either way, but let me research it. There is something about how to set the polarity by how it's first set up, but I can't remember off the top of my head.

#2 No, don't do that with the battery. That will ruin the battery at best and at worst, blow it up. It's just hooking the positive post to ground and negative to the starter.

 

[GJS]

#1 I think the generator can run either way, but let me research it. There is something about how to set the polarity by how it's first set up, but I can't remember off the top of my head.


#2 No, don't do that with the battery. That will ruin the battery at best and at worst, blow it up. It's just hooking the positive post to ground and negative to the starter.

Thanks for the help on this. I usually pretty good at getting something back together if I was the one that took it apart... unfortunately this was an absolute basket case when I got it back.

 

[Big_John]

This should help. You are setting the polarity of the generator.

 

[Big_John]

 

[Big_John]

You can look for some other videos on polarizing the generator, but those two were the first ones I came across that didn't go on about uncle Jeb's old John Deere.

 

[Big_John]

The other thing that I didn't mention is usually, the starter will run on negative or positive grounds. That doesn't make sense as it's a DC motor, but it's a DC motor that doesn't have permanent magnets and polarity doesn't matter as it creates the magnetic field.

 

[GJS]

That’s perfect. I totally missed those videos as I was searching for something different. Thanks a lot for that!

The starter doesn’t seem to care about polarity at all. I booked the wires on backwards earlier and it turned over fine.

Awesome! Thanks again.

 

[Davea Lux]

The generator will work with either a positive or negative ground as long as it is polarized to type of ground that is in use. A word of caution, if your system has a positive ground, you should probably keep it as there is no real advantage to changing. A lot of these older tractors had induction type ammeters, those are the ones with a single wire running along the back of the ammeter. If you change the ground from positive to negative, the ammeter will run backwards.
When the generator is installed, the field is grounded to the generator case, the generator is grounded to the engine block. The positive or negative cable is grounded to the engine block. All you really have to do to change the polarity of the generator is to span the bat terminal to the field terminal on the generator, a short touch with a screwdriver is all it takes.(Do this with the battery hooked up)

Dave

 

[GJS]

The generator will work with either a positive or negative ground as long as it is polarized to type of ground that is in use. A word of caution, if your system has a positive ground, you should probably keep it as there is no real advantage to changing. A lot of these older tractors had induction type ammeters, those are the ones with a single wire running along the back of the ammeter. If you change the ground from positive to negative, the ammeter will run backwards.
When the generator is installed, the field is grounded to the generator case, the generator is grounded to the engine block. The positive or negative cable is grounded to the engine block. All you really have to do to change the polarity of the generator is to span the bat terminal to the field terminal on the generator, a short touch with a screwdriver is all it takes.(Do this with the battery hooked up)

Dave

Thanks, Dave. Hopefully I'll have a self charging system by tomorrow!

 

['66 Fury I]

While I concur with the good advise, I wonder if this machine has magnito ignition? If so, no more need be said. If, however. it has battery ignition, pay close attention to coil polarity. Reverse polarity on the coil will/could cause weak ignition. The "old-timer's" test is to hold the lead of a pencil so that the "fire" from a plug wire jumps from the wire to the pencil lead and on to the plug or engine ground. The "fire" should jump to the lead sharp & clean and then "spray" to ground. If the reverse is true, simply reverse the connections at the coil. LC

 

[GJS]

While I concur with the good advise, I wonder if this machine has magnito ignition? If so, no more need be said. If, however. it has battery ignition, pay close attention to coil polarity. Reverse polarity on the coil will/could cause weak ignition. The "old-timer's" test is to hold the lead of a pencil so that the "fire" from a plug wire jumps from the wire to the pencil lead and on to the plug or engine ground. The "fire" should jump to the lead sharp & clean and then "spray" to ground. If the reverse is true, simply reverse the connections at the coil. LC

It’s magneto. ... should be starting it today, just a few more details with the wiring.

 

[HWYCRZR]

Wow, it has been a long time since I have seen positive grounds. Growing up we had a swather and international or Ford truck that was backwards like that. I remember dad always telling us to be careful if we had to jump start.

 

[GJS]

Man, I got nothing. I polarized both at the VR and at the field terminal (after doing it at the VR failed) nothing. Showing nothing on the ammeter or at the battery (at any RPM). I tore the system back down, took the belt off and it motored so I assume the gen itself if ok. I just have no lights or charging. The field and armature connections seem fine so I’m assuming the VR is crap... though I can’t understand why, it’s 5 years old and never been used.

jeez and here I was worried out a smoke show.

 

[GJS]

Ah.... guess, um...
Guess I should have taken this off the gen entirely when I cleaned the points up.. sort of embarrassing.

Here's what I don't get though, I'd assume that if this regulator was working and I ran it backwards, there'd be a smoke show of sorts. If I was getting nothing when it was running before, it's not going to make any difference whether I'm neg or pos ground at the battery, correct?

I wonder if I shouldn't get a new neg ground VR. I was really hoping I could figure this out without buying anymore crap.

 

[GJS]

Bunch of needless confusion, stupid questions and bad grounds later:

leadin’ the ole Chairge. Thanks for the help, guys.

 

[3175375]

Bunch of needless confusion, stupid questions and bad grounds later:

View attachment 423961

leadin’ the ole Chairge. Thanks for the help, guys.

Great!

I will await the debrief...

 

[GJS]

Great!

I will await the debrief...

Not too too much to say really. I’d determined that the VR was meant for POS ground (as it was marked as such) so I basically cleaned all grounds and verified continuity (for charging and for lights) then I polarized it for POS ground (neg jumpered to armature post briefly) and that was about it. I still don’t understand why nothing bad went down trying to run it neg ground but...

I noticed the needle jumping around at higher RPM which I’m assuming has something to do with the brushes sticking in the gen. It sat in sort of crappy conditions after it was built 5 years ago. I’ll have to pull that and clean everything up, see if I can correct that.

Anyway, that’s that. Got a few things to button up today but the tractor is one step closer to done... nearly ten years after starting it..