[Tommy]

I'm not big on coincidences, so when a new problem arises right after I've done work on a car, I suspect I unknowingly did something while doing the previous work. And electricity takes the path of least resistance, so the arcing tells me there is too much resistance where the electricity is supposed to be going. If it were me I'd start by adding some temporary jumper cables to know the engine and ignition are properly grounded to see if that caused the arcing to stop. If so, I'd start looking for the bad connection(s).