Weirdest Electrical problem I've seen

So i got my 03 Interceptor (non abs) 2 weeks ago. 60000k miles when I got my hands on it. And after I got it all caught up on all the maitenance the last guy didn't do, I've almost got it perfect.

Here's the problem: It's draining my battery and it's not the regulator rectifier. I know it isn't the RR cause I just installed the new one two hours ago and tested both old and new. All voltages input and output are perfect.

Tested the Stator according the the service manual. Also perfect.

When the bike is running, it puts out about 12-13 volts, tops at any RPM. Putting a Multi-meter on the RR output matches the battery.

If I disconnect the battery and let it run only on the charging system at idle, I get 10 volts.

With the slightest throttle, i can get 13.5. but before i get near 2000 RPM, the power cuts out completely.

If I disconnect output from the RR and run only on the battery, i get 16.4 from the disconnected RR's output.

When everything is all hooked up as it should be, my bike runs fine until it drains the battery.

I have no idea how to begin diagnosing this issue. Please help.

Also I apologize for posting if this has been solved before. All of my search results were only pointing to the RR

Thank you.

 

Check for AC on the DC side of the RR. If one leg shorts it will pass AC instead of DC. AC will not charge a battery.

 

Do a reverse-current leakage test ( shown in manual) by placing an ammeter between the battery + terminal and the large red wire that attaches there (after you disconnect that wire) with the key OFF. It's my understanding that running the bike with the battery disconnected can ruin some electrical components, likely the r/r or stator.

Did you already check condition of wires at the starter relay plug and stator-to-r/r plug ??

 

Did you follow the diagnostic algorithm on page 17-5 of the Honda shop manual? Also, did you check for continuity between the stator and ground? Did you test the stator with the motorcycle running, described in the above link?

Seems like the battery, R/R, and stator are ok based on what you've said so far. This suggests a wiring or grounding issue. Has your motorcycle had the recall done? The 3P connector should be inspected and cleaned (contact cleaner). Also all the grounding points should be inspected and cleaned. You should also check the wiring and connectors between the R/R and battery, including the 30A fuse.

Also, if you don't have one already, you might want to consider installing a VFRness.