Yeah, if after re-checking your wiring, then suspicion the bendix spring in the starter. Even though it's a new starter, it most likely is a rebuilt one, and the tech may not have rebuilt it right. If, after you check the wiring, I'd take the starter out and take it to autozone or some other parts place and have it checked. Been there, done that. Turned out it was the starter. But the frying of the wires bothers me. It takes a short in the wiring to cause that. If it was mine, I'd rip out that homemade wiring and replace all the engine compartment wiring with a new harness.