Power drain on kz750

Just got my 79 kz750 back together and running. Bought a new battery but I am having to charge it daily. The bike seems to have a power drain and I am not sure why.

Any ideas?

Does this happen while riding or when the bike is just sitting with the engine turned off? Ed

When the engine is turned off. I could let it sit all night and then the next day I have to charge it again.

Do you have access to and knowledge of an amp meter, fluke, vom anything like that? If so, pul your fuses out and put your amp meter across the fuse holder one circuit at a time. You should have zeroczero current flow. If you find flow, you find your faulty circuit. If no flow on any circuit, your problems will lie in R/R . Good luck. Paul

If you have a multimeter or voltmeter you can test for parasitic drain at the battery. With the key off disconnect one of the battery cables (either one, but only one) and hook the voltmeter between the battery terminal and the battery cable you disconnected from that terminal. You should see zero voltage. If that is the case the battery probably has a problem. However, if the meter reads voltage with the key off there is a short somewhere. Let us know what you find. Ed

Good stuff guys, thanks! I will try those ideas out this weekend and report back.

Hi
I've just he tried this on mine. Disconnected red terminal and put a meter between the red terminal and red lead and I'm getting full battery voltage with the key off.
Is this bad news?

With the ignition key off, you should have zero (no) voltage if the meter is connected correctly. How old is the ignition switch? It may be failing internally.

It would be helpful if you would add your bike’s year & model to your signature line - not all KZ’s have the same wiring layout.

Although it may be normal to see a tiny bit of voltage flowing (less than 1 volt) with the key off, if you are seeing full battery voltage flowing from the positive battery terminal to the positive battery cable with the key off there is a problem. If this was the case on my KZ650-C1 I would hook the positive battery cable back up to the battery and start by testing for full voltage at the main fuse just as you did with the positive battery cable. If full voltage is flowing through that fuse circuit with the key off I would trace the problem through the ignition switch (which may be at fault). If the main fuse shows little no voltage with the key off I would then test to see if the starter relay had full voltage (because it is not on a fuse). If it does not, I would check for full voltage at the rectifier/regulator. Your bike may be different, but on mine the only 3 circuits attached directly to the positive side of the battery are the 20A main fuse, the starter relay, and the rectifier. Everything else is attached through those 3 circuits, so finding which of those 3 is passing full voltage with the key off would narrow down the troubleshooting quite a bit. Ed

Fantastic.
My bike is a bit of a mish mash I think. Should be a kz1100 a3.
That's gave me a good start. I'll follow this through and let you know what I find.
I've just did an amp draw test through the negative lead and terminal and there's no current draw there when the key is off.
Thank you very much!

Traced this to the self cancelling indicator side switches.
When I disconnect that switch the voltage disappears unless I turn the ignition on.

Great! Thank you very much!!!

Good find! You gotta love it when you know for sure you nailed down the source of a problem. Ed