need 4 pin info for sony xec 505

I recently added a Boston Pro 8" sub to my system and rather than using the HU or amps to control signals I'd like to go back to using an old in-dash Sony XEC-505. Problem being, I've lost the 4 pin harness for power. I tried looking for a manual and other info on Sony's site but it's too old for them to have info. I'm simply hoping someone can help me figure out the 4 pins so that I can create a DIY harness.

Using an Ohm meter, touch and hold the black lead to the chassis of the EQ, then touch the red lead to each of the pins until you find the one that shows a short to ground. That is the ground terminal.   Now put your meter to the diode test function, black lead to ground, then touch the red lead to each of the other 3 pins, write down the reading you get on each pin. Now reverse the leads red on ground terminal, touch black to each pin, write it down. One of the pins should have read near .500 one way and a larger number with the leads the other way. This wire is the constant power wire. One of the other 2 is your remote wire.