TOPIC:

I seem to have a charging problem with a 1981 KZ550 where after properly charging a new battery, within the next three days the bike won't start as you can actually hear the battery draining. I already replaced the regulator/rectifier and will look to replace the alternator but wanted to know if there is a way to test the regulator/rectifier or alternator. I even tried installing a battery kill switch which seemed to work for a while but now even when the battery kill switch is set to disable all electrical functions the bikes light are turning on! Any help would be greatly appreciated. Thanks Glenn

Hey Glenn,
Check out this link

www.electrosport.com/electrosport_fault_finding.html

This should be able to help you get your charging system sorted out.

you can actually hear the battery draining

What does a battery sound like when it is draining?? Does it sort of whimper and loose its charge:unsure:

The bike trys to start but after several attempts the lights begin to fade, the horn begins to sound like a kids bike horn and finally there is no engine rev, just some type of starter relay sound.

gkranis wrote:

I even tried installing a battery kill switch which seemed to work for a while but now even when the battery kill switch is set to disable all electrical functions the bikes light are turning on!

This battery kill switch, isitmeant to disconnect the battery fromthe bike totally? If so, and the lights are turning on, then it is installed incorrectly.

Don't throw away the reg/rec, it is probably ok. You can't easily test it properly off the bike. I would hold off on getting an alternator. They rarely ever go bad on the 550. I've only seen them damaged from crashes.

It sounds more likely you have some wiring problems. You will need to start by doing some voltage tests. Measure the battery voltage while it's at 3000 RPM sustained. It should eventually reach at least 14v.
I assume the electrical system is stock, correct?

The battery kill switch was installed correctly because for the first several weeks the after removing the key, the battery was disabled from the bike and only in you inserted the key and set it would the bike start. It seemed to at least be a quick fix as the battery retained it's charge. Why the lights started turning when the key was removed I believe is part of the problem.

how did you install the kill switch, it should either disconnect the ground or positive at the battery, there should be no way to have power thru the kill switch unless the kill switch has gone bad

gkranis wrote:

you can actually hear the battery draining.

What's that sound like?

If you haven't pulled any of the components, you can test your charging system with a volt meter.

Start the bike and set the meter to read DC voltage. Put the voltmeter probes on the battery terminals and read the voltage. You should get 14 to 15 volts when you throttle up to about 4000 rpms. Normally, you can see the voltage increase as you increase engine rpms, and it will hit a maximum voltage, and won't go any higher. That's your voltage regulator clipping the voltage so it doesn't fry your battery. If you're charging OK, and your battery is in good shape, then the problem's with a hot wire that's draining the battery when the bike is sitting.
But if your battery's been discharged a few times, it may be ruined, and won't hold a charge, even if everthing else is working right.
Good luck!

I installed the kill switch to disconnect the ground and I agree there should be no power thru the switch and that's exactly how it was working until recently when the ignition key was turned on and there was power to the bike. Imagine my surprise when this happened. The first thing I looked for was to see if I forgot to remove the kill switch key after riding but that wasn't the case. Maybe the bike is haunted!

Trying to diagnose the problem without knowing how the wiring has been changed is going to be next to impossible. You installed a kill switch to try and stop the battery from draining instead of trying to troubleshoot and fix the underlying problem. Your best bet is to get a wiring diagram and a VOM and start tracing the wires. I would also remove the kill switch you installed because the bike already has a kill switch factory installed on the handle bar. You would be better off disconnecting the battery and removing from the bike or using a battery tender for the times that the bike sits (ie. during the winter..etc.)

gkranis, You asked me offline how to check this problem out and I gave you a pretty detailed answer. Now I am hearing that you installed a switch in the ground wire and the ignition remains hot even with the switch cutting the ground? Somebody has wired ANOTHER ground to the frame somewhere... The whole ground system is wired together but someone has taken a ground off the main harness and tied it to the frame; look around the battery box for a black or black/yellow wire going to a bolt somewhere. That is just a guess as the new ground could be most anywhere. If the battery is draining while the bike sits for awhile more than normal voltage drop, then someone has wired SOMETHING drawing power that isn't going through the ignition switch. Check to see if the coils are warm with the bike off and not having been ridden and check for lights being on.

Thanks for all your help! Will work on the bike this weekend and let you know the results.