Gtxracer

I'm hoping someone can help me out with my TC lockup issue, I'm at my wit's end. Truck is a 98.5 24v, only real modifications are a BHAF and Edge EZ. Trans was rebuilt about 100k ago with billet torque converter and full R&R. I've been chasing a locked torque converter issue for months. After researching the issue I tried a number of different fixes. Flushed and filled the trans, pulled the valve body and inspected, replaced lockup solenoid, checked lockup spring, bypassed the trans cooler, and finally checking for AC noise. Upon checking for noise, I used a cheap DV and came up with 30V AC. Used a Blue Point Pen-Probe style DVM and the AC voltage fluctuated and was well over 0.1VAC. Replaced alternator with O'Reilly reman and same readings. Returned that reman and put in the existing alt. Removed the 140A fuse for the alternator and issue remains. Seperated the ground from the loom on the back of the alternator and covered with aluminum foil. Issue remains. I tried adding another ground from the battery to the body of the alternator, no change. I then tested the system, with the 140A fuse for the alternator removed, and there is still 2.48V AC at the bridge of the fuse and fluctuating at the battery terminals. What is going on??? How is there AC noise when the alternator fuse is removed? Couple more details - the TC will lock and unlock. Not on the highway, it's usually fine there. When cold, it behaves normally. After warming up, the TC will lock. It also will unlock randomly and stay unlocked for a little while. If I turn the truck off while it's unlocked, then start again, the TC will usually lock. Is my PCM toast? ECM? Did my alternator fry everything already? The VP44 and lift pump were replaced about 40k ago. Help!