Transfer Flow AUX Tank

[Erik Dickinson]

This might sound a little odd, or like science fiction. I'm installing a 75 gallon in bed auxiliary fuel tank in my 2020 GMC Sierra 3500 Denail not a big deal. So i thought! My previous 2006 GMC Sierra 2500 wasn't very difficult so i figured an hour or two to move the tank over.My last installation in the 2006 I tied the tank module into the truck sending unit just below the driver side rear door purple wire, black wire in line with the module. Easy no need to drop the tank and unhook the fuel pump sending unit connection. With that said does anyone know why it's true that in the the same location drivers side below the rear door in the 2020 wire bundle i cant find the purple with blue, and the black with green wires? Which are now the new colors of the sending unit. Anyone that can find a diagram with color codes that would be awesome. I spoke with the Transfer Flow guy and they've heard GM has ran the positive sending unit wire along the drivers side, and the negative wire along the passengers side. I'm really trying not to drop the tank and this is why i just went into the main bundle plus it was a lot cleaner that way. In the pics i got from Transfer Flow it shows the wire colors, and gauge now used at the fuel pump sending unit in the 2020 rig.     

[777]

Did you ever get an answer or figure out the color and location for the sending wire ?