SUNL 150 Electrical problems please help

[scooterick52]

The head light and running tail light would not work! Found that they run off the stator. replaced stator, that fixed it, or so i thought and then at high rpm they blew out. so I replaced the the rectifier and that did not fix the problem. so I wired the tail light and headlight to power and they worked but I still cant get the battery to charge. I have replaced the stator twice and the rectifier 3 times and still nothing, I have found no shorts or anything of that nature. any Ideas or trouble shooting tips would help. Im not an electrical wiz especially with AC current on bikes

[wireburn]

Day-um, that's a lot of scooters. I'm sorry to say this, but with what I've heard about SUNL you're better off pushing it off a cliff and collecting the insurance.

-Mike

[scooterick52]

I guess I cant tell my customer that. I said I could fix it, Now Im just pissed and its more of a pride thing I guess. (im Stumped)

[jackthefuzz]

nah scooter, listen brother, you have a short somewhere. its intermittent, its going to be in the wire that powers the headlight circuit and you are correct in that it a wire that comes off the stator. generally that wires color is going to YELLOW. check out the wire diagrams available on this site and track it down. FOR SURE thats what your problem is

[Admin]

I'm not an electrical whiz either but it just has to be either the magneto or voltage regulator. Also, consider that the batt may not be charging just because it's a crappy battery. I don't make it a habit to bash any scooter but Sunl always seems to make the bottom of the list anywhere you look. Good luck.

[earlwb]

Since it looks like you tried a lot of things. Is this a new bike or one that has been on the road for a while?
if used a while and it used to work OK, then a wire has likely come loose or shorted someplace. I guess like dawg thought it might be a bad battery too.
if new then .... It sort of makes me wonder if there is a wiring error in there someplace.

[scooterick52]

this guy bought it at a storage auction and it only had 10 miles on it so id say it is new. I have torn into this wiring and I must say these china bikes have the worst wiring ever! its a mess with electrical tape covering 10 wires soldered together? Does any body know the exact way to test this regulator? or if they have diffrent properties because I ordered one from Powersportsfactory and parts for scooters and still nothing. I can charge the battery and it will hold a charge for a while. it has sat for a week and still held a full charge

[Admin]

I wouldn't lump all china bikes in the Sunl, but you are right. Many of them are really bad with wiring. I have had lights burn out on two Chinese bikes. The first one turned out to be the connector to the voltage regulator wasn't connected properly. The second one turned out just to be some weird deal with a batch of bad bulbs. If you've replaced the regulator, I would suggest you check the wiring to the connector and make sure the connector is good. The regulator should keep the current going to accessories at 12+ a little V. It's a sign that it's not being effective if the lights are blowing at higher rpm's.

[earlwb]

This is the method used to check a car's voltage regulator. The RPM used would be different on a scooter, but it would be the same method.
You just need an accurate voltage meter.

Connect the meter to the poles of the battery. Start the engine and avoid spinning her up, even not for a short moment. The reading of the meter now can be anything; a reading lower than 12.6 volt indicates a weak battery.

Slowly increase the engine speed. The meter reading should increase too, but will get "catched" at an engine speed somewhere at 1000 rpm. (8001200) From then on the reading will stay "locked". It should be 13.8V; 0.5V higher or lower is the limit of what is acceptable. A voltage too high is NOT good: it will ruin your battery and wear out bulbs and other equipment!

A voltage regulator is good when the reading hardly reacts to change of engine speed or to adding power consumers like electric windowheaters or main headlights.

[WarrenS]

Electric window heaters??? Oh you are talking about cars ;D

[fulltimerart]

I will go along with earlwb on the system testing. If its a sealed or solid state regulator it cant be adjusted but the system can be tested with a known good one (sometimes the new ones are no better than the bad one you already have!). Also check the wiring crimps inside the plastic connectors-sometimes they are loose. Good luck. Art PS What part of south Texas are you from?

[scooterick52]

I will tear it down tomorow, the thing that realy confused me (its a5 wire stator) the yellow wire from the stator was spliced to the lights before the regulator. so they would run straight off the stator originally and they would blow out so I spliced them. now im wondering if maybe the wires are in the plug wrong and might be shorting the regulators out and then if run long enough making the stator go bad. any one have a pic of their plug on the same stator set up? I will post more tomorow once I take it apart and do more troubleshooting.
south Houston
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if you live close you should check it out
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[jackthefuzz]

thats corect. the yellow is unregulated and goes to power headlights. more rpms = more voltage. thats why the lights dim at idle and get very rbight at speed. for shts and giggles you may want to carefully check your tail lights as both unregulated ( running lights) and the regulated 12V ( brake lights) come together there. if the stator in fact blew the first time around ( blew meaning ZERO voltage coming out on the yellow wire while the engine is running then you have a short) also its very possible that the regulator is whats gounding