I had the same problem with another truck that the PO rebuilt the engine and installed the ground from the block to the frame but grounded it to the motor mount (engine side) instead of the frame side of the motor mount. Take some jumper cables and ground the block to the battery 
I will check that tonight. I really hope that's the problem. That's the only wire I moved when I did my OBA system. It should have been grounded good enough, basically sandwiched the ground between the bolt & the AC compressor bracket. I even sanded the bracket. I also tried moving the ground to the passenger side motor mount and it still didn't work.
