Parasitic Battery Drain

I have a 79/80 xs650. Like most mine had the typical charging system problem. I replaced the charging system with the Permanent Magnet Alternator Kit from Mikesxs. I also replace the TCI ignition with the Pamco Electronic Ignition Kit #14-0902 from Mikes as well. Everything for the most part seems to be working. Instead of only being able to ride a half an hour I can now ride a couple of hours. The problem now is after I ride and let the bike sit overnight, the next morning the battery will be deep. I have replace the battery with a Everlast AGM battery. I took this battery to an auto parts store to trickle charge and test the battery. That came back good. I can also say I let the battery set for 2 days not connected to the battery and this morning popped it back in and roar we were off. SO I'm looking for suggestions on how to run down this parasite. Should I replace the wiring harness? If so is there one I can buy that will work for my upgrades? Or is there a systematic way to track this problem down?

Easiest way to isolate a parasitic drain I now of is to connect a ammeter in series between the battery and the main bus. I am assuming everything on your bike is fused. With the ignition off, your ammeter should show current flow if you have a parasitic drain. Start removing fuses one at a time and repalcing them until the current flow stops when a particular fuse is pulled. Once it does, you can further isolate by removing ground from each item supplied by that system until the current flow stops. Once you find the faulty circuit, do a ground isolation test on the wiring, and check the component.
Make sure and check them all, and don't assume that the first thing you find is the smoking gun. Could be more than one circuit, but you won't know for sure without checking them all.
Hope this helps.

My daughters bike did the same thing. I found out if the key is turned all the way to the left the tail light stays on. Later it did it again and the key switch was bad.

I disconnect the ground from the battery and connect a test light in series( between the battery negative and ground cable) if the test light illuminates there is a drain, like JD750ACE says remove the fuses one at a time making sure the main fuse is pulled last.
at some point the test light should extinguish, re-install the fuse.
Start with that circuit and remove one item at a time until the test light extinguishes again.
That is where you will find your problem.

I think I would start with the reg/rec remove the red wire from the battery or starter solenoid and see if the draw goes away.

Hope this helps
V/R
Riksoto