Battery not charging

[craigo]

Hello All, long time no see. My bad...

I took a short ride yesterday when all of a sudden, the engine was cutting in and out causing a bucking bronco ride. I got her home and checked the battery voltage. It was 11.9v so I put it on the charger overnight. Now the battery is at full charge so I started her up. Long story short, my charging system is not working. I see voltage dropping off quickly.
So can anyone offer a clue as to where I should start first? Manual says I should take apart the generator and test the stator and voltage regulator. Before I do that, should I check out anything else that might be the culprit?

Thanks in advance,

CraigO

[red]

Long story short, my charging system is not working. I see voltage dropping off quickly.
So can anyone offer a clue as to where I should start first? Manual says I should take apart the generator and test the stator and voltage regulator. Before I do that, should I check out anything else that might be the culprit?  Thanks in advance,
CraigO

CraigO,

Dirty battery terminals can keep a battery from charging.  The gray powdery corrosion that you may see there will act like an electrical insulator.  Clean them with a wire "toothbrush."   You want bright-metal to bright-metal contact, there.  Use new battery bolts, if you can get them.  Battery stores should have some, if the bike shop does not.

I do not have a wiring diagram for your bike, but there may be a fuse between the battery and charging system.  If so, replace that fuse, good or bad (trust me).  Any fuse contacts (or any connectors in that line) also need to be clean and bright.  Use contact cleaner, and join then separate each connector several times.  If a connector has melted, which does happen on the FJs, you can get new factory-type connectors from several on-line electrical specialists.

Cheers,
Red

[craigo]

Thanks for the reply Red. Call the connectors are clean and as new.




I'll look into the fuse issue.

CraigO

[FJ1100mjk]

Did you pull the red one apart that is in your pic, and look at its internals?

Is someone nearby you that has a known good generator, that you can swap yours out with, and see if the problem lies within your generator? Its very little work to do it. You may have to go into (take the generator's end cap off) and do resistance checks between the rectifier and regulator's pins to determine if there's a problem with either. There are other tests too, such as for open/broken windings, worn brushes, and such too, while you have the end cap off.

I don't think there's a fuse inline anywhere for the charging system.

[craigo]

Just replaced that connector with new. Same problem.   

Looks like a new generator is in order.

Thanks again for the help.

CraigO

[FJmonkey]

Craig, Steve likely has a spare working generator you could use to test before you pull the trigger on a new one. I call him and confirm.

[craigo]

Thanks Mark, really appreciate that. Was going for a ride today but this put the kabash on that.

I spoke with Randy @ RPM and he walked me through the test process. The problem is in the generator. He's checking to see if he has a spare one in his shed. If so, I'll most likely buy one from him. 

Hope you're doing well. I need to look at this site more often.

CraigO

[craigo]

Came apart without to much struggle. Even having to work on the garage floor. As I get older, those lifts look more and more appealing.

CraigO

[movenon]

What did you find out ? Alternator or regulator ?  Looks like a soft floor to me  .
George

[wildfire]

A tip I got from a Honda Mec 3 months ago to check a stator on my Honda Shadow. Since the FJ uses the same battery charging physics it should work.  At first I thought Hmmm but  then tried it out and it was true.

Start the bike, using jumper cables from a good source (but no battery in the bike circuit) and bring it up to  2500 rpms. Remove the jumper cables. Expect a drop in rpm's but the bike should still run .

IMPORTANT. Only let the bike run for a few seconds. If it runs after jumper cables are removed the Stator is OK and its time to check the regulator/rectifier with a Ohmn meter

[craigo]

The Rectifier and stator are both shot. I used the Yamaha factory service manual and the Haynes manual tests. Both with the same results. Just be cheaper to get a good used generator and be done with it.

CraigO

[ribbert]

A tip I got from a Honda Mec 3 months ago to check a stator on my Honda Shadow. Since the FJ uses the same battery charging physics it should work.  At first I thought Hmmm but  then tried it out and it was true.

Start the bike, using jumper cables from a good source (but no battery in the bike circuit) and bring it up to  2500 rpms. Remove the jumper cables. Expect a drop in rpm's but the bike should still run .

IMPORTANT. Only let the bike run for a few seconds. If it runs after jumper cables are removed the Stator is OK and its time to check the regulator/rectifier with a Ohmn meter

That wasn't a tip, it was a recipe for disaster. NEVER, EVER, disconnect the battery on a running motor.
Why do you think he said it was important to only do it for a few seconds? Because the risk starts the instant you disconnect the battery.
The older the vehicle (less sensitive electronics) the more likely you are to get away with it but that is all you are doing, getting away with it. Then one day you get caught and fry everything. If the regulator is affected, the voltage can reach many times the 12v the system is rated for.
It's not even a conclusive test, if the motor cuts out the instant you disconnect the battery it could be because you just cooked some other component.
Our FJ's don't have a lot of sensitive electronics which just minimises the risk, it doesn't eliminate it but they do have an ECU and an alternator.
Do it on a modern car and God help you, same goes for accidentally putting jumper leads on the wrong terminals.
There are some here who may rebuff this warning because of the source (perhaps they should ) or because they have gotten away with it in the past, but this is important, if in doubt, look it up. I'm sure any reference you find will tell you the same thing.
While trying to stay away from mechanical issues on the forum, I would hate to see this adopted as the new quickie test for alternators.
Noel

[wildfire]

A tip I got from a Honda Mec 3 months ago to check a stator on my Honda Shadow. Since the FJ uses the same battery charging physics it should work.  At first I thought Hmmm but  then tried it out and it was true.

Start the bike, using jumper cables from a good source (but no battery in the bike circuit) and bring it up to  2500 rpms. Remove the jumper cables. Expect a drop in rpm's but the bike should still run .

IMPORTANT. Only let the bike run for a few seconds. If it runs after jumper cables are removed the Stator is OK and its time to check the regulator/rectifier with a Ohmn meter

That wasn't a tip, it was a recipe for disaster. NEVER, EVER, disconnect the battery on a running motor.
Why do you think he said it was important to only do it for a few seconds? Because the risk starts the instant you disconnect the battery.
The older the vehicle (less sensitive electronics) the more likely you are to get away with it but that is all you are doing, getting away with it. Then one day you get caught and fry everything. If the regulator is affected, the voltage can reach many times the 12v the system is rated for.
It's not even a conclusive test, if the motor cuts out the instant you disconnect the battery it could be because you just cooked some other component.
Our FJ's don't have a lot of sensitive electronics which just minimises the risk, it doesn't eliminate it but they do have an ECU and an alternator.
Do it on a modern car and God help you, same goes for accidentally putting jumper leads on the wrong terminals.
There are some here who may rebuff this warning because of the source (perhaps they should ) or because they have gotten away with it in the past, but this is important, if in doubt, look it up. I'm sure any reference you find will tell you the same thing.
While trying to stay away from mechanical issues on the forum, I would hate to see this adopted as the new quickie test for alternators.
Noel

I did give the short version and I was already aware that a electrical charge has to go somewhere.. He is head bike mechanic at Honda for 20 years and he warned of potential disasters and must ONLY be done if you have narrowed it down to definately  rectifier/regulator or stator and for no other reason.If the r/r is bad the charge from the stator can equally cause damage to electrical components. If the stator is bad it will only make minimal or no charge and the bike engine  will stop running..

As you said never to be done on an engine with numerous electronics.

[Capn Ron]

A tip I got from a Honda Mec 3 months ago to check a stator on my Honda Shadow. Since the FJ uses the same battery charging physics it should work.  At first I thought Hmmm but  then tried it out and it was true.

Start the bike, using jumper cables from a good source (but no battery in the bike circuit) and bring it up to  2500 rpms. Remove the jumper cables. Expect a drop in rpm's but the bike should still run .

IMPORTANT. Only let the bike run for a few seconds. If it runs after jumper cables are removed the Stator is OK and its time to check the regulator/rectifier with a Ohmn meter

That wasn't a tip, it was a recipe for disaster. NEVER, EVER, disconnect the battery on a running motor.
Why do you think he said it was important to only do it for a few seconds? Because the risk starts the instant you disconnect the battery.
The older the vehicle (less sensitive electronics) the more likely you are to get away with it but that is all you are doing, getting away with it. Then one day you get caught and fry everything. If the regulator is affected, the voltage can reach many times the 12v the system is rated for.
It's not even a conclusive test, if the motor cuts out the instant you disconnect the battery it could be because you just cooked some other component.
Our FJ's don't have a lot of sensitive electronics which just minimises the risk, it doesn't eliminate it but they do have an ECU and an alternator.
Do it on a modern car and God help you, same goes for accidentally putting jumper leads on the wrong terminals.
There are some here who may rebuff this warning because of the source (perhaps they should ) or because they have gotten away with it in the past, but this is important, if in doubt, look it up. I'm sure any reference you find will tell you the same thing.
While trying to stay away from mechanical issues on the forum, I would hate to see this adopted as the new quickie test for alternators.
Noel

I too, read the "pull the battery" advice and cringed.  With all the options for charging/using battery banks on the sailboat, I rewired and installed switches that make it very difficult to "break before make" the connections while the diesel engine is running.

[Pat Conlon]

Yes, NEVER disconnect your battery on a running engine...your charging system will go into "full tilt boogie" and smoke shit...
Like your voltage regulator to start with, then connectors, then....