Hi John,
Sounds like a current sense circuit is still reporting an incorrect value and the OS is continuously getting an interrupt for it. I recommend giving your logic board more cleaning, focusing on areas around the battery connection. Any slight changes in the impedance of the current sense resistor caused by foreign contaminants can wildly throw the value off.
Thinking about it further, we could narrow down the problem by trying to run the laptop without a battery. This should prevent any of the power management circuits relating to the battery from reporting anything (as it shouldn't be active). If our suspicion is correct, the 4SNS IPBR sensor shouldn't report anything. Could you give that a try?
Regards,
Michel