This is on my '79 KZ1000:
The battery has not been getting a charge at all, and slowly loses voltage until I have to recharge it myself. I checked the red/white wire that goes from the rectifier to the positive terminal on the battery, and it shows a voltage of 5.5V at idle, and increases to over 10V upwards of 3K rpm, but only when not connected to the battery. With the red/white wire connected to the battery, the voltage does not increase at all with the rpm's, and slowly drops as the engine runs.
I'm really stumped on this one. Any help will be greatly appreciated