Stumped. Tsunami installation into P2K GP9

[Gary S]

Just for the sake of argument let say the red wire bolted to the frame is for the right pick up. Assuming the red wire screwed to the frame is meant as an electrical pickup for both trucks. Am I even close?

Tetters, I am 99.9% certain that your thinking is correct on the red wire. The red wire attached to the frame is the "pick-up" from the opposite side of the trucks from the black wires. In other words, there is a black wire from 2 wheels on the front truck and a black wire from 2 wheels on the rear truck. All four of these wheels are on the same side of the loco. Now, the other four wheels actually use the frame as part of the electrical circuit... and the frame has the red wire screwed to it which is essentially "two red wires" because it is the pick-up wire from both trucks on the "red" side.

A bit more explanation: Just like on an Athearn loco, the metal piece that holds the brass bearings for the wheels on the "red" side is bent horizontal on top of the truck and the metal chassis sits on this. So, there is an electrical circuit from the track to the wheels to the bearings to the metal piece to the frame to the screw to the red wire.

Does this mean I can wire up the Truck leads to the board directly to the decoder then "splice" the red wire to the corresponding pad on the decoder.

Black wires can go to each end of the decoder as in the instructions. The red wire only needs to go to one end of the decoder. There is no need for two red wires because the "red wire attachment points" on each end of the decoder are electrically connected together in the decoder.... there is essentially a "red wire bus" running the length of the decoder. You may even be able to see the conducting trace on the bottom or top of the decoder.

If you have an ohm-meter, you can verify all the red wire and black wire stuff... sit the loco on a piece of track and then verify that the black wires have continuity to one rail, and the red wire has continuity to the other.

I just took the shell off of a P2K GP30 and it has one red wire from the frame to the decoder. I did the meter test on the GP30 and it has continuity to the frame on "red" side and not on the "black" side.

If you wanted to, you could further dismantle the loco and solder a red wire to the metal "bearing holder" pieces at each truck so you're not relying on the chassis/truck joint to carry current.

Hope this makes sense.