New Jarduino build gets started

[daplatapus]

Got a question for all you wiring guru's. I want all my components housed by my arduino, I really don't want anything sitting on a heatsink. For ease of replacement/service, I also didn't want to link the LED's to each other. I want to be able to remove a fixture and not have it affect the other 2. So I have thus far gone to fairly great lengths in planning to accomplish that. BUT, turns out I'm 1 wire short to my fixtures, DU'OH!!!!!!
I have 8 strings of lights = 16 wires. My fan requires 3 wires for power and PWM and the heat sensor for the heatsinks require 3 wires. For a total of 22 needed wires. But the wire I have only has 21
Is there any way I can share a wire in the fan/sensor circuitry? Or am I going to have to run 1 single wire for my sensor or fan?