Electrical system power drain

I have a 78 KZ650 and there is something in the electrical system that is causing a rapid drain of power. I turn on the ignition and the neutral light fades out within 5 seconds. Is there a common root for this problem, or a particularly bad component? I just cannot pinpoint it and am wondering if this is a known issue.

How old is the battery? Ed

Charge the battery, disconnect it, check the voltage, then again in a few hours.
Steve

The battery is older but it holds it charge. I've tested it at multiple times with a voltage reader. I'm thinking there is a faulty component somewhere.

Take the battery to an auto parts store and have it load tested. Checking it with a voltmeter without a load doesn't tell one much about the battery's condition. Ed