Okay, here goes:
The main issue is that the sub is not working at all.
1. For the F.A.S.T. Harness: PWR & AMP Turn-On Wire connected to the same constant 12V wire from the HU. Speaker wire-level inputs all connected to appropriate rear speaker wires.
2. Voltage tests confirm approx. 12.5V from both PWR and AMP wires, approx. 5.5V from all speaker wires, ground is solid.
3. Subwoofer OHM tests indicate 1.7 OHMS for the 2 OHM sub.
4. The amp unit itself has been sent to SAS and confirmed working in perfect condition.
Now, I performed a small test:
On the back of the amp circuit board, if only the AMP wire and GND are connected, the AMP wire reads 12.5V. HOWEVER, when PWR is connected alongside the AMP wire and GND, both PWR and AMP wire lose voltage (they actually fluctuate near 50 millivolts, not nearly enough to power the amp). BUT, if just PWR and GND are connected, PWR reads approx. 150millivolts.
Strange, I know! Please help! I can't figure out why this is not working when all of the connections indicate that the amp has power.
Thanks in advance!
P.S. I just thought about something: Due to the 2012 Focus using a data bus system, I have the AMP wire connected to a constant 12V source and am relying on the Signal Turn-on Loop (the Orange loop at the connector point) to turn the amp on and off. Should I disconnect the AMP wire to use this Loop?