[CA] problem with extension for wiring

[rb56]

i went to install my dragonfly 4 on my mini pontoon and found once under the console (mine's in the middle of the deck) i had run out of wiring to go further up. i had to order the extension and it came and is almost the same as the original. it has the plug to connect to my unit cord, it has the plug to connect to my unit and has a wire like mine...that contains 3 red, black and grey exposed wires. on my original i had already connected those and had power to the unit. i assumed if i just taped off the 3 ends would be ok but no. once i did that i connected to the unit and turned it on and nothing. i disconnected the unit and went back to it's original wire plug and turned it on and it came on. do i need to also wire those 3 in to the connections my original wiring went to?