Backside of Instrument Cluster

75 Dodge Dart Sport.

Removed my instrument cluster about 2-3 months ago to swap out the gages and change to LEDs. No it's time to reinstall it in the dash.

Problem - The 3 slots on the rear of the cluster. I know the voltage regulator wire goes in the center slot, but I can't find any lose wires that go into the other slots, and I don't remember actually removing any wires from those slots.

Any help would be appreciated.

Jim
Jacksonville, FL