changing from pos to neg

[kenbob]

Could someone (Maybe JoeWa) tell me what I need to do to change my 12v gen from pos to neg. I got most of it: Change battery cables around, swap wires on the coil, swap sides on the ammeter, but then do I need to polarize the generator? I have had 2 tell me I do not. (I am using the same generator). If I do have to do it, how? The voltage regulator isn't super easy to get at (311). I am a bit challenged on the elecrical side of things.

Why? I am geezering up my tractor by adding a bunch of LED lights and I could not find polarity neutral lights, only neg ground. THanks all.

 

[wore out]

Could someone (Maybe JoeWa) tell me what I need to do to change my 12v gen from pos to neg. I got most of it: Change battery cables around, swap wires on the coil, swap sides on the ammeter, but then do I need to polarize the generator? I have had 2 tell me I do not. (I am using the same generator). If I do have to do it, how? The voltage regulator isn't super easy to get at (311). I am a bit challenged on the elecrical side of things.

Why? I am geezering up my tractor by adding a bunch of LED lights and I could not find polarity neutral lights, only neg ground. THanks all.

Many/most LED lights have have two wires leading out of them and can be used with with either ground polarity depending upon how the wires are connected.

If you can't find lites like that and choose to swap the polarity of your generator charging system, YES the generator will need to be polarized BEFORE startup and be aware that some quality VR's are designed to function best/have the longest life when operated at the polarity they were designed for.


I'm not against alternator conversions that require the system polarity to be swapped, but can't see doing that just to accommodate LED lites. YAMMV!

 

[mEl]

Some regulators are marked POG and NEG but not all. you can try to see if it works but at any rate you must polarize it when changing system polarity. Since the regulator is in a bad spot I would take a wire and fasten it to the battery + post, disconnect the field wire at the Gen and touch the wire to the generator F terminal and make it spark a couple times. Polarizing is changing the Generator fields windings and shoes from North pole to South pole magneticlly so the Gen outputs the right way, You do not polarize the regulator, hopefully the regulator cooperates.

 

[kenbob]

Many/most LED lights have have two wires leading out of them and can be used with with either ground polarity depending upon how the wires are connected.

If you can't find lites like that and choose to swap the polarity of your generator charging system, YES the generator will need to be polarized BEFORE startup and be aware that some quality VR's are designed to function best/have the longest life when operated at the polarity they were designed for.


I'm not against alternator conversions that require the system polarity to be swapped, but can't see doing that just to accommodate LED lites. YAMMV!

not putting in an alternator, just changing polarity. I tried those lights pos ground and no go.

 

[mEl]

not putting in an alternator, just changing polarity. I tried those lights pos ground and no go.

Are they 2 lead lights, if they light hooked up backwards use them that way, I have seen polarity sensitive lights in some applications in truck trailer applications with some of the older dump trucks Pos ground.

 

[kenbob]

Are they 2 lead lights, if they light hooked up backwards use them that way, I have seen polarity sensitive lights in some applications in truck trailer applications with some of the older dump trucks Pos ground.

2 wire and definitely do not work when hooked backwards. They are 3/4" lights that I am putting in the implement mounting holes in the front. Only ones I could find to that spec. 4 lights to a side with 2 bolts in the middle holes.

 

[mEl]

2 wire and definitely do not work when hooked backwards. They are 3/4" lights that I am putting in the implement mounting holes in the front. Only ones I could find to that spec. 4 lights to a side with 2 bolts in the middle holes.

I guess just for clarification then the lights will not work hooked up either way? That seems strange! Ido not know what color code they use but normally red is Pos and black is Neg. on light wires. Maybe they have some sort of a polarity protection built in, will they light off a battery?

 

[kenbob]

I guess just for clarification then the lights will not work hooked up either way? That seems strange! Ido not know what color code they use but normally red is Pos and black is Neg. on light wires. Maybe they have some sort of a polarity protection built in, will they light off a battery?

They light up even when using a small 9v battery to test them. Not so when wired backwards.

 

[wore out]

2 wire and definitely do not work when hooked backwards. They are 3/4" lights that I am putting in the implement mounting holes in the front. Only ones I could find to that spec. 4 lights to a side with 2 bolts in the middle holes.

Can you post the make and part number of the LED lamps?

 

[mEl]

They light up even when using a small 9v battery to test them. Not so when wired backwards.

That being the case I do not see why you could not just wire them opposite on the tractor, if you have wires run to the mounting spots you should just be able to hook them up opposite of Neg ground and they should work. I prefer dedicated ground wires from the lights ran back to a common ground eliminating bolts and brackets as paths to ground as after years they tend to rust and get erratic. You should be able to use the ground to the light hot wire and the light ground wire to the light switch, if it works with a 9 V it should work with tractor voltage, go to a place where you know you have voltage on the tractor and try it both ways to see what happens, it should work with the wires opposite the way they would if 12V neg.

 

[Jim.ME]

2 wire and definitely do not work when hooked backwards. They are 3/4" lights that I am putting in the implement mounting holes in the front. Only ones I could find to that spec. 4 lights to a side with 2 bolts in the middle holes.

Do they have a ground connection through a screw mount hole the ground wire is hooked to? Forget thinking power and ground. With two wires as long as the LED wires are isolated from the mount they should work, as long as the positive wire goes to positive and the negative to negative. They would only be wired backwards on a positive ground system if you are not hooking positive wire for the LED to positive (the ground) and the negative LED wire to negative (the power source).

 

[kenbob]

Can you post the make and part number of the LED lamps?

I think these are it mine have chrome rings instead of black.

https://www.amazon.com/Purishion-Clearence-Indicators-Trailer-Taillight/dp/B01MEG40NI/ref=asc_df_B01MEG40NI/?tag=hyprod-20&linkCode=df0&hvadid=312089957955&hvpos=&hvnetw=g&hvrand=

 

[mEl]

Do they have a ground connection through a screw mount hole the ground wire is hooked to? Forget thinking power and ground. With two wires as long as the LED wires are isolated from the mount they should work, as long as the positive wire goes to positive and the negative to negative. They would only be wired backwards on a positive ground system if you are not hooking positive wire for the LED to positive (the ground) and the negative LED wire to negative (the power source).

Jim, the discussion to begin with that started the Pos / Neg thing was changing system polarity to run the LED lights. My point is that the LEDs should work on a POS system if the lights normal POS wire is hooked to the Chassis and the normal ground to the wire from the light switch unless I am missing something. I ran into this years ago when we sold a new Lo Boy and hooked it to an older Mack tractor some of the lights lit but most didn't, we had to switch the bulbs polarity. If the bulbs have polarity they would not work on a POS system hooked up normally but should work if the normal hot wire on the liht is hooked to ground which is POS 12 V.

 

[Jim.ME]

Jim, the discussion to begin with that started the Pos / Neg thing was changing system polarity to run the LED lights. My point is that the LEDs should work on a POS system if the lights normal POS wire is hooked to the Chassis and the normal ground to the wire from the light switch unless I am missing something. I ran into this years ago when we sold a new Lo Boy and hooked it to an older Mack tractor some of the lights lit but most didn't, we had to switch the bulbs polarity. If the bulbs have polarity they would not work on a POS system hooked up normally but should work if the normal hot wire on the liht is hooked to ground which is POS 12 V.

We agree, that is what I was trying to relay as well. Positive hooks to positive and negative to negative. If the system is positive ground, that is where the positive wire on the light goes. His picture of the lights, that is available to see now, supports that.

 

[kenbob]

Jim, the discussion to begin with that started the Pos / Neg thing was changing system polarity to run the LED lights. My point is that the LEDs should work on a POS system if the lights normal POS wire is hooked to the Chassis and the normal ground to the wire from the light switch unless I am missing something. I ran into this years ago when we sold a new Lo Boy and hooked it to an older Mack tractor some of the lights lit but most didn't, we had to switch the bulbs polarity. If the bulbs have polarity they would not work on a POS system hooked up normally but should work if the normal hot wire on the liht is hooked to ground which is POS 12 V.

I get it now. I will try that. I have some gauge lights with small bulbs that may be an issue, the headlight and tail are neutral regarding ground.

 

[mEl]

I get it now. I will try that. I have some gauge lights with small bulbs that may be an issue, the headlight and tail are neutral regarding ground.

Glad to see that you see what Jim and I are saying, The dash lights won't care which polarity they are as long as they are the original old style filament bulbs.

I get it now. I will try that. I have some gauge lights with small bulbs that may be an issue, the headlight and tail are neutral regarding ground.

 

[kenbob]

Thanks for all the help. I will let you know how that turns out soon.

 

[kenbob]

Thanks for all the help. I will let you know how that turns out soon.

Fiddled with the lights all day. Tried connected through the switch, and direct to the battery. They will not light either way except negative grounded. Done with changing polarity except for flashing the gen.

 

[Jim.ME]

Fiddled with the lights all day. Tried connected through the switch, and direct to the battery. They will not light either way except negative grounded. Done with changing polarity except for flashing the gen.

I don't know what you have going on, but I use those same type 3/4" lights and as long as the black wire goes to negative power source and the other color wire (white, yellow, red, whatever) goes to the positive power source they will light.

 

[Jim.ME]

I don't know what you have going on, but I use those same type 3/4" lights and as long as the black wire goes to negative power source and the other color wire (white, yellow, red, whatever) goes to the positive power source they will light.

I don't know how your latest reply post to me on this ended up in a voltage regulator thread on the JD Forum, but it did. Here is a link to it.

Thread on JD Forum

In reply to that post on the JD Forum. It appears you are now about complete with converting the tractor to Negative ground, so this won't matter to you, but it might to someone reading this in the future. If the LED lights, light up from a battery when the black wire is on negative and the other wire (white, yellow, red, whatever color it is) is on positive, they should light on your positive ground tractor as long as the black wire gets power from the switch and the other wire (white, yellow, red, whatever color it is) goes to ground, which is positive for a positive ground system. There is no need to rewire the lights to change the wires, electricity does not care about the color wire. Color is used only for identifying which way it goes for people installing them. Just hook the wires up to put power (negative) from the switch to the black wire and ground (positive) to the other wire (white, yellow, red, whatever color it is).

I am sorry if I am wrong in my thinking, but I have to believe you got hung up believing the Black wire had to be the one to go to ground, which is wrong on a positive ground system. I say this since you now have mentioned needing to switch the wires inside the light in your latest post.