When I try and plug in my new esc to a battery pack, sparks come from the connection as if the polarity is reversed (I even tried reversing the polarity, that didn't help). I own 2 other GTBs, I know how to wire them, and I haven't modified anything on this one.

Also, it only does this when the input harness is plugged into a receiver. I tried connecting the esc to a battery without the harness in the receiver, no sparks. And oddly enough, it does it whether or not the switch is on.

I ahve also tried a normal input harness from a regular gtb and tried plugging it into a regular rx, still the same problem.

Thanks for any help guys
Chris