changing from pos to neg

[mEl]

Jim, I do not understand why the lights can be made to light when hooked up negative ground on a battery but not when the positive post is hooked to the chassis, when the positive post is hooked to ground the whole tractor chassis becomes positive and the negative post becomes the return path for the current flow. I know some may get tired of me saying it, but I hold a Federal License which I had to pass theory tests to obtain in Electronics and speak with some knowledge and also throw in 50+ years of working as lead mechanic. My specialties were electronics and hydraulics. Hooked up positive ground on the tractor should just require hooking the wire up opposite and changing the internal wiring of the light is not at all necessary. Saying any more will not help him at this point, it is all in print repeatedly. Also, if the system is working as is there is no need to reflash it, none at all.

 

[Jim.ME]

Jim, I do not understand why the lights can be made to light when hooked up negative ground on a battery but not when the positive post is hooked to the chassis, when the positive post is hooked to ground the whole tractor chassis becomes positive and the negative post becomes the return path for the current flow. I know some may get tired of me saying it, but I hold a Federal License which I had to pass theory tests to obtain in Electronics and speak with some knowledge and also throw in 50+ years of working as lead mechanic. My specialties were electronics and hydraulics. Hooked up positive ground on the tractor should just require hooking the wire up opposite and changing the internal wiring of the light is not at all necessary. Saying any more will not help him at this point, it is all in print repeatedly. Also, if the system is working as is there is no need to reflash it, none at all.

Agreed. His last post (needing to switch the wires inside the light) says to me he was always grounding the black wire, which would be wrong with a positive ground. Just trying to get that out there for those reading this in the future.

 

[kenbob]

Jim, I do not understand why the lights can be made to light when hooked up negative ground on a battery but not when the positive post is hooked to the chassis, when the positive post is hooked to ground the whole tractor chassis becomes positive and the negative post becomes the return path for the current flow. I know some may get tired of me saying it, but I hold a Federal License which I had to pass theory tests to obtain in Electronics and speak with some knowledge and also throw in 50+ years of working as lead mechanic. My specialties were electronics and hydraulics. Hooked up positive ground on the tractor should just require hooking the wire up opposite and changing the internal wiring of the light is not at all necessary. Saying any more will not help him at this point, it is all in print repeatedly. Also, if the system is working as is there is no need to reflash it, none at all.

I grounded it to the battery. I tried the frame but got nothing, but did not really screw it to the frame of the tractor I will give that a try.

 

[kenbob]

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.

I know which wire is which as I have tried them on a 9v radio battery. For ground I went to the battery. grounding to the frame did not work, but I did not screw it down. I will try grounding to the frame with the pos wire.

 

[mEl]

You MUST switch the wires that are going to the light, try taking a wire from the battery Neg to one side of the bulb and grounding the other to the tractor frame. if it does not work with the wires at the light switch the wires, it has to work, we are missing something here!!! I am assuming you are still Pos ground.

 

[kenbob]

Yes pos ground. Going at it again today. These are Chinese lights of course. Maybe they have a different way of doing things.

 

[kenbob]

Ok! First I want to thank everybody for sticking with me on this. Yes they now work without changing polarity on the tractor. I am not even sure what I was doing wrong in the past, but today it works. However, I have another weird thing going on. I am putting in a wood dash on my 300. I thought that meant all my 2 wire gauge lights would have to be grounded. I tield them all together, but now it seems everything works and I don't even have the ground hooked up? My guess is since they are all tied together, they are being grounded by the tach cable??? I also have an aftermarket gas gauge. The tank is full. When I turn the switch on, it excites and pegs to full for a second and then drops back to zero. When I turn on the lights, the light comes on on the first notch, but goes out when switched if full on. It is the only gauge that acts that way. Since it is pos ground I switched the wires on the gas gauge and it doesn't do anything with the wires switched. A whole new thing for you experts to think about. Again thanks for working me through the first problem. I will post a picture of the working Leds later.

 

[wore out]

Ok! First I want to thank everybody for sticking with me on this. Yes they now work without changing polarity on the tractor. I am not even sure what I was doing wrong in the past, but today it works. However, I have another weird thing going on. I am putting in a wood dash on my 300. I thought that meant all my 2 wire gauge lights would have to be grounded. I tield them all together, but now it seems everything works and I don't even have the ground hooked up? My guess is since they are all tied together, they are being grounded by the tach cable??? I also have an aftermarket gas gauge. The tank is full. When I turn the switch on, it excites and pegs to full for a second and then drops back to zero. When I turn on the lights, the light comes on on the first notch, but goes out when switched if full on. It is the only gauge that acts that way. Since it is pos ground I switched the wires on the gas gauge and it doesn't do anything with the wires switched. A whole new thing for you experts to think about. Again thanks for working me through the first problem. I will post a picture of the working Leds later.

GOOD for you to keep at it until you got the LED lights working!

It would be a good idea to run a new, dedicated ground wire to the instruments, including your new gas gauge.

Does it's illumination bulb have two lead wires, or a single one?

As to the gas gauge, there are several ways of making them, thermally-operated gauges aren't polarity sensitive, magnetic movement gauges may or may not be affected by polarity, based upon their design.

It seems STRANGE, what you are seeing with the gas gauge, "it excites and pegs to full for a second and then drops back to zero".

When you get it properly grounded I wonder if it will act differently?

It acts like it's some sort of electronic gauge???

 

[mEl]

Glad you seen the LED thing through and let us know, you will learn a lot as you go along, I would not be surprised if the gas gage is polarity sensitive, POS ground stuff is not to common. I do not know if you could change the wires on the back of the gage, it would be worth a try. Sticking my neck out a bit I would say the dash gages do not need a separate ground but grounding them will not hurt. Check and see if the instructions with the fuel gage mentions grounding it.

 

[Jim.ME]

Glad you seen the LED thing through and let us know, you will learn a lot as you go along, I would not be surprised if the gas gage is polarity sensitive, POS ground stuff is not to common. I do not know if you could change the wires on the back of the gage, it would be worth a try. Sticking my neck out a bit I would say the dash gages do not need a separate ground but grounding them will not hurt. Check and see if the instructions with the fuel gage mentions grounding it.

The other thing with the aftermarket gas gauge is, Did the sender come with it? The gauge and sender ohm ranges have to match. If you are using the old sender, do you know the ohm range it uses and the ohm range of the aftermarket gauge?

Glad to hear you got the lights figured out.

 

[kenbob]

The gauge is adjustable to the ohm range of the sending unit. I have had the gauge quite a while. I thought I had it adjusted, but maybe it is not correct. It is just a button to push on the back of the gauge. I must have had something grounded I did not know it. I went to town to get a connector nut for the oil pressure gauge and when I got back I did have to plug in the ground from the leds.

 

[kenbob]

Gonna try and load a movie and pictures. The guage had a 4 wire plug that I inserted. REd+blue- orange for the light. Black goes to the sending unit. I am going to take it out tomorrow. I thought the plug only went in one way, but maybe it doesn't. Movie too big to load. Picture of the dash shows key in on position. When I pull the ligth switch all the way out, all other lights work and the gauge light goes out.