ESC Not Arming

[Mortificate]

Ok heres the issue. I just installed the Freestyle Belt mod on my CPP. I obviously no longer need the 3 in 1 as I am running the park 370 with 20amp esc. I am also running the G90 gyro so with the ESC and Gyro I shouldn't need the 3 in 1. When I remove the 3 in 1, though, the ESC wont arm anymore. It will beep just once (EFlight 20 AMP) than nothing. The way I see it the wireing should be pretty simple, Battery plugged into the ESC, ESC plugged into the BL Motor.
Can anyone think of what the problem is?

[Gino CP]

ESC bec power lead is disconnected :mrgreen:

[txflyer]

yup with the 3n1 i run the bec through the 3n1 and the gyro.. when i was trying to run a tail esc i had to reinstalled the bec pin on the esc plug

[Mortificate]

Yep that was the problem. I had forgotten that I pulled out the BEC power lead on my ESC. Woops. I knew it was gonna be an easy fix.