I have a 2002 vulcan 750 I just bought. It would not start a few days after buying it, so I thought the battery was probably weak, so I bought a new one, then that one went dead as well a couple weeks later. The bike runs fine once it's started, even with a dead battery, I push started it. I'm not to familiar with smaller engines, but in a car that would mean the alternator is fine because the car can't spark without it, so the "charger" on the bike is okay isn't it? All the connections are beautiful, I've never seen such good clean contacts on all the wires. Does anyone have an idea why it's not charging my battery? I'm at a loss. Are there any fuses I need to be checking, I don't have a repair manual yet so I don't even know where to look for fuses.

Thank you much.

 

Recently had a similar problem on my 2002 Vulcan 750. Needed to have the Regulator Rectifier replaced. Problem was eliminated.

 

Sounds like the regulator/rectifier or the alternator
I suggest you get a "Clymer Manual" for your particular bike
and a "multimeter" ($20.00 or so)
Look at the troubleshooting tips for the "charging system"
I was having the same problem with my '81 KZ 750 LTD
and was able to understand the steps you need to take to
diagnose the problem: i.e.reg/rec or the alternator
I have not yet tried to do the repairs but these items have "de-mystified" the
diagnostic procedures greatly

 

My 1990 did the same thing last year......90 miles from my house at a charity ride up north. It turned out the voltage regulator went. Unfortunately when that happened the stator couldn't take the charge and cooked. Jut barely fixed it without taking the motor out. But it still cost I think $140 in parts and $275 cash for labor (couldn't do it myself).