New Jarduino build gets started

[daplatapus]

Well, I fired up my Jarduino for the first time with everything hooked up. All the new cables, temp sensor for water and heatsink fans, etc. So far it looks like all the LED circuits are working as planned, the temp sensors are working, but I can't get the heatsink fans to run. Hmmm, no idea why. According to the drawing I have for the fan circuit, it says to use PWM pin 45 on the Arduino and pin 48 for the fan enable, but I went through the sketch and I think it's actually PWM pin 44 and 47 for the enable. So I used those but nothing...
Temp is holding steady at 27.5 C. I turned down the temp value so the fan should have come on at 20C. If there's a PWM signal from the arduino, where and what would I measure in the circuit?