200 HPDI battert drain

[Peeyow12]

Having issues with battery draining overnight.
Little back ground information:Installed a newer 200 HPDI engine using an older EFI wiring harness and controls. Also when connecting the engine positive and negative to the battery, I am getting a little spark and can hear something on the engine click. One last thing, are the multi-function gauges from the EFI engine compatible with the 200 HPDI? Currently they are not powering up.
Thanks

[Peeyow12]

Found the problem

I found that there was a ground wire that was disconnected going to the multifunction gauges. Once connected, the gauges started working and the spark on the battery stopped. We left the battery hooked up all night and the voltage stayed at 12.6 volts without any drainage.