Tail light not working By jerimiah (Read 11,622 times)

[jerimiah]

I have a 49cc 2007 chinese scooter and the tail light stopped working last night also the dash board illumination light stopped same time. Both bulbs work.The brake light works fine. There are 2 elements in the same brake/tail light bulb. Before the tail light stopped it would run off the stator electricity and the brake light would run off the battery. I checked the wiring diagram on line  but my colors are different. I found a plug at right rear of scooter that feeds the harness going to the rear light assembly. The brown wire in the plug goes to the tail light and so does a brown wire go to the illumination bulb socket on the dash. After looking at wiring diagrams that aren't exactly like mine I see that the yellow wire usually feeds the tail light.... so I jumped from a yellow wire that was in a socket that was not used by the scooter to the brown wire going to the tail light bulb. Now when the scooter is running the tail light works and the dash light works. I have no idea where the brown wire is suppose to get it's positive from as I checked all plugs for continuity that had a brown wire in rear and front. Do you think I will hurt the electrical system the way I fixed it? Does anyone know how and where that brown wire is suppose to get it's electricity?

[Alleyoop]

When you turn on the KEY TO ON it contacts a black wire which in turn feeds the things that need juice so look in front the brown wire might have pulled out of a plug. The brown wire also feeds the instrument panel.

[Bashan]

The Big Guy is 100% spot on. The brown wire is DC 12v. Yellow is AC 12v and energizes with the stator. Running just the tail and dash as an extra load will not hurt anything, I've did it. In fact I've ran all of the lights off of the yellow and used the white as charging and it worked fine. We can try to find the brown and hook it back up but you'll have to pull some plastic. You actually run into problems when you try to run a single phase G-Y-W stator while using just the yellow or white as the energy source. It's designed to split the load. You will be fine using the yellow as you are, ride on.

This is a generic diagram, not specific for your bike. Note the brown to the back which is actually the black. Sometimes the black runs to the front and sometimes the brown does. The brown always runs to the back.

[jerimiah]

Jul 26, 2014 21:51:38 GMT -6 Bashan said:

The Big Guy is 100% spot on. The brown wire is DC 12v. Yellow is AC 12v and energizes with the stator. Running just the tail and dash as an extra load will not hurt anything, I've did it. In fact I've ran all of the lights off of the yellow and used the white as charging and it worked fine. We can try to find the brown and hook it back up but you'll have to pull some plastic. You actually run into problems when you try to run a single phase G-Y-W stator while using just the yellow or white as the energy source. It's designed to split the load. You will be fine using the yellow as you are, ride on.

This is a generic diagram, not specific for your bike. Note the brown to the back which is actually the black. Sometimes the black runs to the front and sometimes the brown does. The brown always runs to the back.

Thanks for the info and wiring diag. Seems like different scootesr have a different accessories running 12vdc and 12vac.  I had a bad battery up till a week ago so it was obvious what was run from the stator 12vac. On my scooter the headlight (high and low beam), and tail light and illumination dash light is 12vac. Now I have a good battery and new rectifier so I can just turn on the ignition without motor running and use the 12vdc to run the blinkers, horn and brake light. It doesn't seem like the 12vdc is running much compared to the 12vac. You mention that you need to split the load between the ac and dc, does it seem like there is any problem in how mine is splitting the ac and dc load??  Also it seems like the black wire coming from the ignition, according to the above diagram, is being fed by the battery 12vdc which then feeds the brown wire which feeds the tail light. But seems like my tail light was running off the stator? Any thoughts are appreciated.

[Bashan]

Let's take an 8 coil stator that is your standard G-Y-W single phase. One of the coils is a seperate mini system that supplies the CDI with AC current. It's the one that's all wrapped up in itelf (red arrow}.

The white wire starts at one end of all of the other coils and snakes around to terminate at the ground wire (green arrow). I know it doesn't look like the white does that but it's a rather circuitous route that doubles back. Believe me, I traced it out, that's how bored I was one winter day. But here's the important part of the answer to your question, the yellow wire taps onto the center of the white wire, the so called center tap. Since it is tapping into the middle of the white wire it makes much less energy because of fewer coils. This is a very simplified diagram to illustrate the configuration:

Look inside the rectifier/regulator, there's a square that is actually a bridge rectifier. You see the white runs directly to one side of the bridge. The yellow however splits off but is regulated to 12v AC inside the R/R. the split is what gives us the yellow with 12v AC to supply the lights. Since the white runs directly to the bridge and doesn't split it is considered "dedicated" to the charging circuit. They never go anywhere without the other one....ba-dump. You can see the red coming off of the bridge and running to the battery with 12v DC and also supplying DC circuits such as lights and the starting circuit..

Thw white and yellow are two sides of the feeds to the R/R. You can think of them in a balance and they push each other back and forth...so to speak. A bigger draw on one pulls from the other. You can do this to some degree and the other circuits within the R/R will compensate. But you can push it too far and roast your R/R. I ran a scooter entirely off of the battery one summer and didn't use the yellow at all. The R/R got kinda hot but it lived to rectify another day. I don't recommend shifting too much one way or the other on an R/R however. But what you're doing with just a couple lights won't hurt a thing. And yes, different scooters have different configurations of what the yellow does. By the way, the wiring diagrams are a joke, they are never right. Your bike is from the bowels of China my friend, it is a different world. Your configuration is fine, the "split" is within acceptable parameters. Also, I think your bike was rewired hence the AC tail light. Did I answer all of your questions? If not ask away. Rich

[jerimiah]

Jul 27, 2014 7:49:26 GMT -6 Bashan said:

Let's take an 8 coil stator that is your standard G-Y-W single phase. One of the coils is a seperate mini system that supplies the CDI with AC current. It's the one that's all wrapped up in itelf (red arrow}.

The white wire starts at one end of all of the other coils and snakes around to terminate at the ground wire (green arrow). I know it doesn't look like the white does that but it's a rather circuitous route that doubles back. Believe me, I traced it out, that's how bored I was one winter day. But here's the important part of the answer to your question, the yellow wire taps onto the center of the white wire, the so called center tap. Since it is tapping into the middle of the white wire it makes much less energy because of fewer coils. This is a very simplified diagram to illustrate the configuration:

Look inside the rectifier/regulator, there's a square that is actually a bridge rectifier. You see the white runs directly to one side of the bridge. The yellow however splits off but is regulated to 12v AC inside the R/R. the split is what gives us the yellow with 12v AC to supply the lights. Since the white runs directly to the bridge and doesn't split it is considered "dedicated" to the charging circuit. They never go anywhere without the other one....ba-dump. You can see the red coming off of the bridge and running to the battery with 12v DC and also supplying DC circuits such as lights and the starting circuit..

Thw white and yellow are two sides of the feeds to the R/R. You can think of them in a balance and they push each other back and forth...so to speak. A bigger draw on one pulls from the other. You can do this to some degree and the other circuits within the R/R will compensate. But you can push it too far and roast your R/R. I ran a scooter entirely off of the battery one summer and didn't use the yellow at all. The R/R got kinda hot but it lived to rectify another day. I don't recommend shifting too much one way or the other on an R/R however. But what you're doing with just a couple lights won't hurt a thing. And yes, different scooters have different configurations of what the yellow does. By the way, the wiring diagrams are a joke, they are never right. Your bike is from the bowels of China my friend, it is a different world. Your configuration is fine, the "split" is within acceptable parameters. Also, I think your bike was rewired hence the AC tail light. Did I answer all of your questions? If not ask away. Rich

Thank you Rich for all the info and explanation and pictures of how the system works. As far as the bike being rewired I am not sure. Right now the tail light works off of the ac and the brake light works off of dc and it is one bulb. Do you think I should rewire it so that the tail and brake work off of dc. I do see an advantage to the tail working off of the ac so that if the battery is dead at night you still have tail light. Also, I have worked on a lot of electrical on dc cars and am confused about a common ground for the ac and dc system. Is this normal in motor scooters?
 Another question in understanding the stator and rectifier you explained and posted a great wiring diagram. I understand that the white wire from the stator goes into the rectifier at a high ac voltage and then comes out of the rectifier as a red wire, 12-14 vdc, to charge the battery. I am not understanding how the yellow wire ac voltage is kept down to 12-14vac by the rectifier.
The yellow wire (according to your diagram) is t'd off from before it reaches the rectifier and feeds the lights. So I don't understand how the rectifier is able to regulate the ac voltage in the yellow wire. I am imagining that the yellow wire would need to go into the rectifier as high ac voltage and have a wire coming out as lower ac voltage Similar to the white going in high and coming out as red coming out low.

[Bashan]

Diagram time!! Here is the stator yellow as it runs through the R/R. Off to the left you see some regulating circuits, in the middle the bridge rectifier. The yellow arrows show the back and forth movement of electrons in an AC current. Yes kids, I know those diodes may look like the wrong electron flow direction, but it's according to what school of thought that you point the diode symbol:

The split on the yellow bypasses the bridge rectifier. The white has no split so the electrons are forced through the bridge and it comes out as DC on the red. Remember, this is AC current, it pulses back and forth and the electromotive force pushes it through the split to ground where it completes the circuit through the stator ground back to the stator frame. Meanwhile, it has passed through the R/R and ground to be regulated. It is one massive flux back and forth BACK AND FORTH and....whew, I seem to have the vapors. That is why the Chinese love the AC to various lights concept. It's simple to get the yellow energized and then run it to various lights, ground the light, boom, you're done. If you put a split on the white it would also be an AC regulated source wire.

Ah, the common ground! Yes, unless it is a three phase system it is almost always a combination of AC and DC. You sir are the first one in four years to ask that question!! I've been waiting for it! And here is my answer....I don't freaking know!! The best I can answer is that electrons ride on the clouds around the nucleus. An electromotive force pulls them along either directly towards the red terminal or back and forth in an AC current. My feeling is there is enough room in the frame for electrons to have a path for both AC and DC current. They probably surf along and share the currents sometimes swapping from one to the other. As long as the call of the voltage is answered it really doesn't matter where they go. I'd be glad to hear other theories. Your wiring config is fine, I personally wouldn't change anything. Technically you are supposed to have the tail light come on with the key. This is just a DOT mandate but I really don't think anybody is going to notice or care. Rich

[Guitarman]

The answer is:

AC has 2 components: Phase and Neutral.
DC has 2 components: Positive and Negative.
There is a fifth component that is common to both: Ground.

I'll leave the rest to your imagination.

[Bashan]

My imagination has come up lacking. I want a diagram Guitar! What he is asking, and I've wondered, is why there isn't a conflict with the electron flow? I've also thought possibly the AC current cycles back and forth from stator to R/R to lights to ground to ground to stator and ad infinitum. So e pluribus unum ergo facto, it never really enters the DC ground. Come to think of it, when you meter the battery you only get DC, no AC. The AC probably won't have anything to do with the DC! Such a snob. Joe's the best guitarist in the world. Rich

[Guitarman]

AC has Phase (back and forth) and Neutral (not moving). DC has Positive (Flowing this way) and Negative (flowing that way). Nether of these has a GROUND component. AC has 3 wires. 2 of them are active. DC has 2 wires both active. But neither one has GROUND. GROUND is for safety purposes. Circuits do not need a ground to work, they just need to connect back to themselves thru the load. Ground is to make the circuit safe to handle for mere mortals. So you can ground them both together because NEITHER one has a ground as PART of it or it's natural circuit.

I'm going to take Bash and put him on this PC board. His job is to run back and forth pushing a button on each side. (Yellow man)

I'm going to put Alley on the other side and his job is to run around the circle and spin the star at every lap. (Blue man)

They are both on the same PC board but they are both separate. If I happen to touch either one then I am adding myself into the circuit and the juice will flow into me, ESPECIALLY if I am GROUNDED. So, I am going to add a line to each one that makes the whole thing safer for me to touch. I am going to ground each one to the dark reddish brown box (representing the Earth)

Now, they are grounded so if I happen to touch them the juice will not flow directly into and thru me. It now flows into the GROUND where it is harmlessly dispersed.

The GROUND is the trash can of the circuit not a vital component. Understand?

[jerimiah]

Jul 31, 2014 18:26:31 GMT -6 Guitarman said:

AC has Phase (back and forth) and Neutral (not moving). DC has Positive (Flowing this way) and Negative (flowing that way). Nether of these has a GROUND component. AC has 3 wires. 2 of them are active. DC has 2 wires both active. But neither one has GROUND. GROUND is for safety purposes. Circuits do not need a ground to work, they just need to connect back to themselves thru the load. Ground is to make the circuit safe to handle for mere mortals. So you can ground them both together because NEITHER one has a ground as PART of it or it's natural circuit.

I'm going to take Bash and put him on this PC board. His job is to run back and forth pushing a button on each side. (Yellow man)

I'm going to put Alley on the other side and his job is to run around the circle and spin the star at every lap. (Blue man)

They are both on the same PC board but they are both separate. If I happen to touch either one then I am adding myself into the circuit and the juice will flow into me, ESPECIALLY if I am GROUNDED. So, I am going to add a line to each one that makes the whole thing safer for me to touch. I am going to ground each one to the dark reddish brown box (representing the Earth)

Now, they are grounded so if I happen to touch them the juice will not flow directly into and thru me. It now flows into the GROUND where it is harmlessly dispersed.

The GROUND is the trash can of the circuit not a vital component. Understand?

Thank you Bashan and Guitarman and Alleyoop for the time and effort to explain this. Guitarman I still have some confusion about your last explanation about ground. In DC there are 2 wires and the frame of the scooter is being used as one of those wires. I understand that a ground is not necessary for ac or dc to work but it seems like the scooter frame is being used as the negative wire and ground. It seems like the AC on the scooter is also using the scooter frame as one of the wires. So my confusion is still in how they can both share the same wire??

[Guitarman]

As long as that wire is a ground, there is no conflict.

[Bashan]

I wanted to add the updated version of Andy's diagram that many of the engineers now use. First, Kronos has been accepted as the universal power source. Also, the AC guy on the right of the diagram has been discovered to be female. In regards to the duality of electron flow in the scooter split AC and DC system, the AC girls boyfriend can be seen on the left interfering with the DC guy by using an electronic whiffy. The various grounds that don't exist can be seen releasing nonexistant lightening bolts. The DC cycle has been discovered to be Jewish for some odd reason that only Andy knows.

[Guitarman]

In other words you didn't understand it at all. LOL

[Guitarman]

Tell ya what... You answer me this and mebbee I not make fun of your haircut.

How does force propagate?