Headlights fade after starting By jarrodtrout (Read 1,781 times)

[jarrodtrout]

Hi,

Hope I get can some help here.

I've got a 2011 150cc Jonway, and I just had to replace a bad stator due to no spark. The scooter now starts up perfectly, and runs fine. However the headlights (taillights and dash lights too) start out bright like they always have, but in about a minute they fade to almost off. They don't flicker or pulse, just fade like they are slowly losing power. Holding down either brake will cause them to brighten some, or revving the engine/accelerating will cause them to brighten barely, but no where near bright enough to drive at night.

Before replacing the stator, they worked fine. Could I have got a faulty stator, that still allows the engine to run fine and charges the battery, but can't power the lights? Or does this sound like the voltage regulator is bad? I tried simply unplugging the regulator but got no lights at all.

Coincidentally, since replacing the stator, the scooter now idles at a higher RPM as well...is this in any way connected?

Thanks for any help!

[JR]

Welcome to the forum! Standard 8 coil stator with white, yellow and green going to the R/R? If so then we need to test the out put of staor on the yellow and white wire. Need to use your test meter, start the scooter and set the meter on AC voltage. Test the wires at idle and at 3to 5k Rpm and see if the voltage climbs?

Let us know your readings and we'll go from there.

JR

[jarrodtrout]

Apr 13, 2013 7:23:50 GMT -6 JR said:

Welcome to the forum! Standard 8 coil stator with white, yellow and green going to the R/R? If so then we need to test the out put of staor on the yellow and white wire. Need to use your test meter, start the scooter and set the meter on AC voltage. Test the wires at idle and at 3to 5k Rpm and see if the voltage climbs?

Let us know your readings and we'll go from there.

JR

Yep, standard chinese 8 coil stator. My setup, the wires go from the stator to a harness. This harness then feeds to the R/R which is in front, mounted to the frame behind the headlights. Should I test from the harness?

[justbuggin2]

i would test at the stator and then again at the R/R did you get the exact same stator as was on there to start with as the stator and R/R need to match

[jarrodtrout]

Ok, I'm fairly mechanically competent, but not electrically so.

I got a $10 multimeter at Walmart. I unplugged the 3 wire connector while the engine was running, and plugged the positive lead into the yellow wire directly from the stator, and touched the negative lead to the frame. Got nothing. I then tried the white, nothing still. Plugged it back it, and tried up front at the R/R. Still nothing. Checked, and it was indeed set to AC. I tested the meter on a battery, and it registered...so I think I'm using the meter right.

Is this right?

And yeah, as far as I can tell, the stator is exactly the same. Generic Chinese 8 coil, everything is the exact same colors, shapes, etc.

[jarrodtrout]

Ok, I'm pretty sure I'm doing something wrong with the meter, or maybe its just not the right kind of meter. I tested the the blue and red leads also coming off the stator (while they were connected, and while the engine was running) and again, the needle didn't budge. Tested the meter again on a AA battery and the scooter battery, and both registered good.

If the engine is running, it doesn't seem possible that no voltage at all is coming from the stator, right?

Was I using the meter correctly? Or is my brand new stator a dud? Is it possible just the white and/or yellow wires are bad right out of the package, but the rest of the stator assembly works?

If the R/R or the stator was bad, would the battery still be charging? Because it starts up fine each time, and the turn signals and brake lights are bright as ever.

Furthermore, how does this explain why the headlights are bright and working when I first turn the scooter on, but then fade away? Could the R/R be pulling too much voltage away?

Sorry for so many questions, but like I said, totally unfamiliar with the electrical workings, and I hate to pay a shop $100 to fix it if I can with a $20 part.

Thanks again for any assistance!

[JR]

Ok let me explain the stator set up. You should have 5 wires, three for the charging going to the R/R and two for the CDI as follows:

Yellow = AC feed for headlights/R/R
White = AC feed to R/R for R/R charging and autochoke
Green = ground

Black/red = AC feed to CDI
Blue/white or red/white = pulse signal; wire to CDI.

Now we know that the black/red and the blue/white are ok simply because the scooter will run, this is their only function to feed the CDI and send a signal to the CDI which gives the engine a spark.

Now on the yellow wire and white wire set your volt meter to at least 100Vac and test each wire to the green=ground. Now here is something else that could be your problem and it's grounding. The black negative battery cable from the battery bolts to the frame and must be getting a good ground, check this connection and make sure there is no paint that could cause a poor ground.

Also the engine MUST be grounded. Generally there is a black wire that hooks up where the black negative battery cable bolts on the frame and then bolts up on the engine on one of the fan cover bolts or to a valve cover bolt. Again if the engine is not properly grounded you can have issues.

If the grounding is good and you test no "AC" volts on the yellow and/or white wire then your stator is no good.

Here is what you're looking for:



JR

[jarrodtrout]

[replyingto=admin]JR[/replyingto]Awesome, thanks for explaining that so thoroughly. Thats kinda what I gathered from reading around, but you explained it very simply.

Just to be clear, plug the black, negative lead from the meter into the green wire on the stator, withe the positive, red lead in the yellow or green wire, also directly from the stator?

[justbuggin2]

sounds like you have a floating ground stator and your R/R needs to made for the same

[JR]

Red lead on meter to the yellow and then black to green wire on the stator and then switch red to white and test too.

JR

[jarrodtrout]

Apr 13, 2013 21:52:05 GMT -6 JR said:

Red lead on meter to the yellow and then black to green wire on the stator and then switch red to white and test too.

JR

Alright, did exactly this, and the needle didn't even move. Checked all grounds, they're fine. I also checked the red wire coming from the stator, and it read properly.

So I'm taking it at this point I got a bad stator right out of the package?

If that's the case, why would the headlights still come on at first? Just curious to understand how that works.

Also, the dash and taillights don't even come on at all now...I think I might have blown them while I had the R/R unplugged and was doing all this testing. Does that sound likely?

[justbuggin2]

i am thinking that the stator and R/R are both bad now and you may have blown the lights out will have to check them with a battery

[jarrodtrout]

[replyingto=justbuggin2]justbuggin2[/replyingto]Well, the store I bought the stator from is sending a replacement, so we'll see how it goes.

[jarrodtrout]

Alright so new stator arrived, put it in, worked great. Then after about 20 mins of driving, the same thing happened: head, tail, and dash lights just stopped working. Havent had a chance to test the voltage from this second brand new stator, but at this point, I think Im going to put in a new R/R anyway, just to make sure.

It seems odd to me that two brand new stators wouldnt be working properly.

Is there a chance I somehow got the wrong stator? It is 100% identical to the one I pulled out.

[justbuggin2]

if the stator and R/R are not match then you are gona have problems yes replace the R/R you should have replaced both at the same time