Electrical Diagnosis By Guitarman (Read 1,838 times)

[Guitarman]

I've read a few times here in the forum that if your battery is dead, but you get a jumpstart and it keeps running, then your R/R is bad. Is this correct?
244cc engine.

[Bashan]

A bad R/R would be one possible reason that your battery died. I wouldn't think the jump start has anything to do with your diagnosis. Use your multi on the battery terminals while the bike is running and with some RPMs. You should get +14v DC, if you don't then the R/R might be bad. Other possible scenarios might be the battery itself is bad, loose cables, or parasitic drain. By the way, if you get a jump make sure the other vehicle is not running. That will fry your R/R. The size of the jump battery doesn't matter, your bike will draw what it needs and no more.

[Guitarman]

I should probably replace my R/R then. I had a jump from another bike and it was running, and once from a car while it was running. I've had charging issues for some time now and keep cables with me.

Also, Am I AC or DC since my headlights do not come on till the bike is running? And does that matter in diagnosing the R/R?

[tvnacman]

post a picture of your stator plug .

John

[Alleyoop]

TWO easy means to determine IF your CDI is AC or DC.
1. Check the Bottom Wire on the TWO PLUG of your CDI, with the KEY ON and if it registers 12volts it is a DC CDI.
2. Start your Motor and disconnect the Battery if it is DC your motor will DIE otherwise it is AC.


Remember Guys, when someone says is my Scoot a DC or AC system all it means is the CDI battery Fed(DCV) or Stator Fed(ACV).
The lights can be driven by either the Battery or R/R which converts ACV to DCV. Also they can be a mix of how they are Fed. Some lights may work off the battery and some off the R/R.
Alleyoop

[FrankenMech]

You can get your battery tested at some parts stores. Ask if they have the proper equipment rated for use with small batteries. Many shops do not have the proper equipment. Charge the battery before you go with a good 0.5-2A charger or they may try to charge it with a regular automotive 30A charger. Charging instructions may even be printed on the battery.

When you have a known good charged up battery check your system voltage at the battery as Bashan suggested. The charge voltage with the scoot running should be 14V +/- 0.5V.

Your voltage regulator may be bad. They are cheap and you should keep a spare around. TVN can supply a good one. There are some instructions for testing a regulator but I would not trust them since there are several different circuits used by manufacturers.

My scoot normally has only a single tiny wire and fuse coming from the battery that supplies power to the ignition switch and everything else. That makes testing for a parasitic drain fairly simple. The ignition switch should turn off everything. The big wire goes to the starter relay. I have additional circuits on mine that I have added.

Alley is correct about the AC/DC scooter question being only about the CDI power supply. His first test for a DC CDI is good. However I would not use Alley's second test for a AC or DC scooter. I have seen too many schematics and vehicles that will continue to run without a battery. Disconnecting the battery also produces 'load dump' transients on the system. It might 'work' with some scoots but personally I don't do it.

[Guitarman]

My phone was destroyed over Thanksgiving and I have a new one on the way. Should be here tomorrow (Monday). Till then, I can't do any pix.

I looked on TVNacmans site and did not find any 250 parts. Maybe I just missed them.

It's been raining for the last 2 days so I haven't been able to get anything done. I'm SO looking forward to riding again.

I have a pretty new battery and I keep it on a battery tender made for bikes.

[FrankenMech]

Did you forget your phone on the beach and the tide came in? My daughter lost one that way out in Santa Monica. Landlubbers forget about tides..... Small lakes and rivers don't have tides. River levels get interesting when dams or storms are involved.

My 'new' scooter had a 'new' battery but it lost a cell even on a battery maintainer.

[Guitarman]

I know better than to leave anything on the beach. LOL

It got dropped and then run over. Not a good combo.
I'm supposed to get my new one Monday, but it might be Tuesday.

My battery is in good shape. As soon as the weather gets better, I'll meter it under some RPMs.

[FACE PLANT FOR LIFE]

I might as well throw my two cents in here (John will know what I'm about to tell you!).

It's very unlikely, but on my scooter, the battery wasn't charging all all despite the R/R being good and the stator being good. If you've ever done any wiring on your bike before this started to happen, see if you can undo it. If the bike came like this, start checking for mismatched wire connections (colors) under your dash and front of your scooter. The reason I say this is because on my scooter, I had done some mismatched wiring on it to make the dashboard and lights turn on when the ignition was turned on, but it came with one side effect: a short to ground. This drained all of my battery voltage away and fried quite a few R/R's (Just ask John. He heard all about it when all of a sudden I had NEGATIVE voltage going to my battery (polarity swap)!

[tvnacman]

Nov 30, 2013 2:39:12 GMT -6 Guitarman said:

I've read a few times here in the forum that if your battery is dead, but you get a jumpstart and it keeps running, then your R/R is bad. Is this correct?
244cc engine.

If your cdi is dc fired ( powered by 12vdc from the battery) and you have a dead battery and a bad regulator the in will shut off .

John

[FrankenMech]

Dec 2, 2013 16:37:20 GMT -6 tvnacman said:

If your cdi is dc fired ( powered by 12vdc from the battery) and you have a dead battery and a bad regulator the in(engine) will shut off .

John

That would be true for a missing, gone away, or completely destroyed regulator. The rectifier portion of an otherwise bad regulator can be even partially functioning and still supply enough current to keep the engine running.

I gave my full size lab-type O-scope away to my nephew that teaches HS Physics and Math. I may have to invest in one of those high end VOM meters that has a 'scope function. Those would be small and handy enough to probe scoot electrical systems. It won't be long before one is needed to work on a new car. Some probably require one already. I feel 'blind' when just using a VOM.

BTW- From what I have seen so far some Rectifier/Regulator circuits are better than others. Some are awful, some are just brute force simple, and others are elegant. But that's just me, I am interested in such things.

[FrankenMech]

Dec 2, 2013 0:09:29 GMT -6 Guitarman said:

I know better than to leave anything on the beach. LOL

It got dropped and then run over. Not a good combo.
I'm supposed to get my new one Monday, but it might be Tuesday.

My battery is in good shape. As soon as the weather gets better, I'll meter it under some RPMs.

Terrible weather in Hawaii, let me cry some crocodile tears for ya! LOL!!!

The high here Wednesday is supposed to be 35°F with the lows hovering in the lower teens for the next week. We don't even have pretty mountains to ski on either or frozen lakes to go ice fishing on.

When you throw your phone at the girlfriend she just might back over it.... ;D

My daughter got herself wet also on the beach. She was sun-bathing and snoozing. When that wave hit she woke up but it was too late for her phone. There seems to be something about water in general and sea water in particular that phones don't like. I just don't understand it either. She has been to the Galapagos islands, other exotic places, and all up the seaboard on both coasts but forgot about tides.... It must be something about exposure to S. California that just kills brain cells.

[Guitarman]

My battery was charging fine for some time and then one day.... Pffft. Time to keep it on a trickle tender.

Weather? Oh man, don't get me started! It's finaly cooling down so that humans can move around safely outside and it rains. Not just a day or two, but it hits for a week or so. And now that my thanksgiving vacation is over, It clears up. I should call Obama and complain. LOL

Amulet, no mods before it quit working, so I doubt that's it. Plus I've been fixing wiring issues this last 2 weeks.

I'll be replacing the R/R just because. I've seen enough different indicators that make me wonder about it.

MERRY CHRISTMAS!!

[Alleyoop]

Nov 30, 2013 2:39:12 GMT -6 Guitarman said:

I've read a few times here in the forum that if your battery is dead, but you get a jumpstart and it keeps running, then your R/R is bad. Is this correct?
244cc engine.

That is not correct, the only reason you got a jump start was so you could use the Electric Start to spin the stater which requires 12volts to work.
So if the battery was bad not enough juice to activate the starter a jumping the battery would send 12volts to the starter.

Now if the motor started and kept running then you have a AC CDI no two ways about it. A DC CDI will not work if the battery is bad or dead.

Now once the motor is running all you need is a VOLT METER to test the R/R and see if it is putting out around 14+Volts. IF it is not then you can test the STATOR if it is putting out 40-100VAC then you
know the R/R is bad. If the Stator is not putting out 40-100VAC then your stator is bad BUT YOUR R/R could also be bad you won't know until you get good VOLTAGE from the STATOR.

For scooters with carbs all you really need is a Decent Volt Meter and a 12V Light Tester for checking wires that feed voltage to lights and or gauges.
Alleyoop