headlights dim unless brakes applied By godfeast (Read 8,790 times)

[04prixgt04]

my issue which took 4 months to figure out (and brand new 11 pole stator RR and new harness off ebay) turned out to just be a wire that was shorting because the mirror was smashing it when i would bolt it on. they get crushed pretty easy. already happened to the new harness also.

[JR]

Would this be the possible scenario if the scooter shop I took this to put in an 8 pole dc stator by accident? I had considered that earlier, but just started thinking about that again and I'm still not sure how to tell for certain *******


I know of no DC stator for any Chinese scooter. Only DC stators I know of are ones people custom make themselves.

The standard 8-pole AC stator has five wires

Yellow = AC output
White = Ac output
Green = ground
black/red = AC feed to CDI
blue/white or blue/yellow = CDI pickup or pulse signal wire

[justbuggin2]

i think you need to get a match set R/R and stator if you get a R/R for the wrong stator or visversa you will be having the same problems

[godfeast]

I went down to the scooter store and got them to give me an exact duplicate of my original RR.

Thunderstorms all day around Orlando have kept me from putting it in and testing further.

If 8 dc pole stators arent normally marketed, that would possibly make things easier to diagnose - I did find a site that said you could check to see if the stator had an engine ground through yellow or white wiring to determine if it was floated and I did check but couldnt find one.

I cant find the site again to reverify if I did it correctly - just put a meter to engine case and to each wire and couldnt get a reading to show ground, but then again maybe I misread what to do. Meh.

[justbuggin2]

OK most stators are ac whether 6 8 or 11 poles if you check the yellow, white , green wires to the center metal part that bolts to the motor and you have an connection there the stator is grounded if you do not have a connection there then the stator is floated ground you need the R/R to match the type of stator you have if you use the wrong R/R for the stator you have you will have problems you can burn up the stator and R/R along with other things

[godfeast]

I dont have access to my puller to take the stator off atm or I wouldve taken that down to the store yesterday as well.

That being the difference, then I should be able to test for ground between those wires and the engine that the metal bracket is directly mounted to then, right?

Having found no ground, would the presumption then be that it is likely floated wither intended to or not?

Rain just let up at noon after two days, so heading out to put harness/rr back in and retest.

[justbuggin2]

yes you can check it with the motor at one lead of your meter and the wires on the other lead

[godfeast]

Im going to reverify this then, because I did check yesterday and both white and yellow leads showed no ground connection to the engine.

Would that not indicate a floating ground and thus a dc only stator? Or maybe a damaged one I suppose.

**** reverified testing the three lines from stator (green,yellow,white)*****

Stator green ground wire grounds to engine

Neither yellow or white grounds to the engine

yellow and white ground to each other

stator ground doesnt ground to either white or yellow

CONCLUSION ?

[JR]

Point blank even if the gound is floated it is NOT DC.

Some stators have a floating ground.. you need to see which it is?.

One type has the yellow and white on opposite ends of 7 coils. (floating ground) The second type has white on one end and on the opposite end a ground (grounded stator - center tap). The yellow wire on these is a center tap.

You got to match the proper R/R to either one. Did your original stator have a 4-pin R/R? If so it is a grounded stator. Most floated ground stators use a 5-pin R/R

Floating ground stator.[/img]



Floating ground stator will not show ohm resistance from yellow/white to ground but rather from yellow to white.

JR

[godfeast]

The stator that came with the scooter was a normal ac stator. My issue is what might have been put in by the bike mechanic, but I think the problem was more likely he gave me the wrong RR rather then the wrong stator and then I compiled the problem by attempting to tie in both ac and dc lines on the taillight led.

Ive put the RR and the harness back in the bike today when rain allowed, and was able to start it by jumpering the plug again.

I tested the brake light and it worked, then tested the taillight, which showed no overlap of ac and dc as it did before.

I am spending tomorrow reworking the instrument dash harness before putting it all back together, but I feel that I've probably fixed the issue with the RR switch.

[JR]

Grounded gy-6 stator and on these stators you will have only the yellow and white coming from the stator to the R/R with the green ground coming from the frame/battery. As you can see the white is on one end of the winding and the green on the other end.

The yellow not seen will be a center tap AC wire and when ohming both the yellow and white will have resistance to ground.

This is very common for 6-coil stator and some people want to call then DC stators but they are not.

.ebay.com/itm/Direct-Current-Magneto-Stator-Gy6-125cc-150cc-6-Coil-5-wire-ATV-Scooter-DC-New-/261099768479?hash=item3ccac24a9f&item=261099768479&pt=Motorcycles_Parts_Accessories&vxp=mtr" rel="nofollow" target="_blank">.ebay.com/itm/Direct-Current-Magneto-Stator-Gy6-125cc-150cc-6-Coil-5-wire-ATV-Scooter-DC-New-/261099768479?hash=item3ccac24a9f&item=261099768479&pt=Motorcycles_Parts_Accessories&vxp=mtr

All scooters use a half wave R/R thus they are AC to DC R/R. This is a very good explanation of how the system works on a typical scooter;



These circuits contain the layout of the battery charger / rectifier circuit. A battery is a pretty finnicky device as far as power input is concerned. The Voltage regulator has to satisfy two goals: 1. provide a DC input source and 2. Provide a voltage of roughly 14 Volts. The regulator employs a rectifier in order to change the power from AC to DC, but it is not used as we are used to seeing it in North America. It attaches on the ground side of the battery as is common in conventional current circuit layouts. Next to the rectifier is the Voltage Sense Deivce, which I can only assume it is driven by a handful of semiconductors. The sensor accomplishes two tasks, it limits the upper charging voltage to 14.4V and charges the battery with more or less current depending on the battery's condition. The battery's positive terminal feeds back into the circuit to help the regulator decide how hard to drive the charger. Under normal conditions, the charger works very little, simply trickle charging the full battery. But as the battery gets weaker, the charger senses less voltage and boosts the charge current. When the battery dies, or the fuse blows, the voltage sensing assumes a completely dead battery and drives as hard as it can. This circuit is current limited so it will not just explode, but it would be a good idea to fix any problems with the battery circuit so that the battery doesn't go completely dead.

The bottom circuit (in the late P200 diagram) is a layout of the AC regulator. The soul purpose of this device is to limit the overvoltages from a high revving engine. As the engine spins faster, the overall voltage goes up past the operating voltage of the headlight. That kind of overvoltage can take out an expensive headlight, so as a safeguard, the power from the stator is routed into the voltage regulator. All power that surpasses a threshold of about 14 volts is shorted to ground. It doesn't matter which way you wire up the circuit for the two "A" inputs, since the circuit is not polarized. This circuit is not current limited, so running with no load (ie dead headlight) will make the regulator overheat. If your headlight goes out and there is no immediate replacement, disconnect the wire from the "A" wire that goes to the stator.


I'll add to this, it's common for the rectifier part to go out and yet the regulator part keep functioning. When this happens you'll have no charge to the battery yet can keep headlights or they may even be dim. But if you remove the R/R or the regulator part of the R/R goes out then with any significant RPM increase of the engine you'll blow the headlight bulbs in seconds.
JR

[godfeast]

I put everything back together and issue is still there.

With new RR in place im getting wot reading of about 40v ac on yellow - i switched the yellow and white leads at the rr and it stayed at a stable 6v ac, but didnt go up at wot - with it the other way im getting the full 40v ac on yellow.

With it this way, as soon as I plug in the llights the ac voltage drops on yellow to 0 and the lights dont work at all.

I also found that the enricher was shorting yellow to ground - when plugged in I was getting no reading on yellow at all ( stator putting out, but unless enricher unplugged, yellow went to 0 volts ac and showed a direct connection to ground).

Not sure what damage this mustve caused, but hopefully the new rr isnt already shot from just running a few minutes with this issue in place.


This is getting to be a bit much in lost time and wasted money at this point. I may not even bother much more.

If anyone has a harness set for these bikes to sell cheaply, send me a pm.

[JR]

You mentioned someone else put in a new stator, IMO it's time to find out just what they installed?

JR

[godfeast]

Going back on Monday. Same store that put strange RR in.

I think all the electronics are shot. solenoid wont turn starter over, brakes switches both ruined, enricher gone, all lights blown again.

I tested the stator for ac and dc and it seems to have both as well - not sure if thats normal, but at this point...

[JR]

Godfeast nothing about this system seems normal? Myself I believe I would figure out how to order the pieces even if you had to get them one at a time from someone else.

There are several vendors here that can help you with correct parts.

JR