Air Conditioning - Outside Unit Constantly Running-Het Pump

Our outside unit will not shut off, even if the thermostat is in the off position. With the t-stat completely disconnected, and the heat pump's wiring disconnected from the control board on the inside unit, it still runs. I just finished installing a new contactor, but to no avail. My question is: Where, exactly is the outside getting its 24v suplly from? It can't be the t-stat or inside control board, so where do i look next? I'd really like to solve this problem myself, before I make a service call.

Have you checked the voltage on the control side of the contactor to be sure it's indeed getting 24 volts ??

Yes it has 24v. I guess i don't understand where it could be getting that 24v from. It is currently unhooked from the control board, but still runs.

You're going to have to trace the wires back from the contactor and see where they go. There may be a secondary xfrmr for cooling and the wires are shorted.