starter turns on when battery hooked up

Could be a bad starter solenoid or perhaps the starter was wired wrong.

Thanks for quick response. Brand new starter. On initial install this issue started. Took back out had it bench tested and all good. Back in it went and still ongoing. Relay and some fuses removed still goes when hooked up.

Did you reverse the wires to the starter?

No not possible. one is pin insert plug and play Other is a big stock end with a protection boot on it.

Did you find out the issue? Having this same problem now