2006 vulcan won't charge

The battery charge voltage should be about 13.5-15.5 volts dc when speed is about 2000-2500 rpm. The rectifier and/or voltage regulator could be bad or the motorcycle could have a wiring issue such as an intermittent connection/short etc.

could be bad resister in system,or charging system needs diagnostic!

What model motorcycle motorcycle is it. I have had a simular problem one time with a customers motorcycle customer brings the bike in for the same problem i charged the battery then checked the charging all normal could not find the problem so asked the customer to take it for a ride being he lived close to the shop it did it again he brought it in and checked it it was charging normal so i just let it run and heat up checked the charging no charging. It was the stator when it hit a certain temp it stopped working you may want to try the same test.

If your battery won't charge it sounds like a voltage regulator or a stator. The stator is basically an alternator, but it is internal behind the flywheel. Sometimes the battery itself won't charge as well. If you need help testing the stator or voltage regulator let me know, I can walk you through it if you have a volt meter. Otherwise a reputable shop will have to diagnose and repair. Daniel

Sounds like you have a bad battery. Have you taken it off and tried to trickle charge it? Make sure you test it and watch to see how fast the voltage is dropping. I suspect though, that the batter is bad or your charging system isn't giving it any juice. If you charge the battery, it should still run for 20-30 minutes even if the charging system is bad. That way you know if it's the battery or the charging system. Good luck!

It sounds like your battery is not getting charged, so you're running your bike with a "total loss" electrical system. Your bike will run--for quite a while if the headlight isn't on--off the stored energy in a battery.

If this were a car, the immediate place to check would be the alternator and / or the alternator belt. With a motorcycle, especially one of this vintage, I would actually start somewhere else. One of the most common reasons that a bike will fail to charge is that it has developed ground issues. Double-check the negative cable attached to your battery. The other end most likely attaches to the engine or the frame with a big bolt. Look for any rust at that mounting point. You probably won't find any, or else the bike would never run very well, but it's an easy first check.

Charging problems I've had with older Honda motorcycles have often been with the voltage regulator or with one or more connectors in the electrical system, rather than with the stator itself. Trace the output wires from the stator to the voltage regulator, which is usually mounted away from the engine (it's often near the battery box or under a side panel). With the bike running, use a volt meter to check two things: (1) output from the voltage regulator; and (2) raw, unregulated output from the stator into the voltage regulator. A bad regulator may be putting out voltage that's too low, in which case the battery's stored energy is tapped to make up the difference. On the other hand, if you're not seeing ANY voltage coming out of the regulator, make sure that juice is being fed into the regulator so it has something to do.

If you're not seeing voltage on the input side of the regulator, the problem has been narrowed to the stator or to a bad connector in between the stator and the voltage regulator. I have seen a number of problems arising from low-quality wiring insulation used in 1980s bikes; it's much cheaper to fix that than to replace the stator in your bike. Alternatively, if you're seeing input voltage but not output voltage from your regulator, I'd suspect you may have found the problem. I believe, though I'm not certain, that Honda still used a mechanical as opposed to digital regulator on this bike, and those mechanical regulators do go bad. You can find used but warranted replacements for not too much money online; depending on how universal the regulator is (Honda used the same voltage regulator in all of its motorcycles from ~1971 through 1978), a brand new one may not be all that expensive, either.

A final, somewhat random thought is that you should also take your battery to an auto parts store to have it checked. A heavily sulfated battery will test out at 12.6 volts, but it won't be able to store its rated amperage. A battery like that may work well enough right after it's been taken off an external charger, but it won't have the amps to turn over the starter after it's been sitting for a while. This doesn't sound like what you're experiencing, which is why I didn't lead off my solution with this suggestion, but a weak battery will put a lot of stress on your charging system and can can lead to some odd symptoms.

Good luck!

Well, if the Batt don't hold charge then check the regulator on the bike with an Ohmmeter you can buy one at an Auto parts shop....motor running you should see 14.5 V if not then the Reg is out!!!

Chk the charging voltage at the battery posts. Should be between 13.6 to 14.2 The lower the voltage the hugher the amps. if at 13,6 it is charging heavy. It may not be your charging system. If it shows 12 volts it is charging max output, and at 15 it isn't doing anything.. I would put my money on the battery being no good..