Sorry for resurrecting an old thread but im in the same boat as many on here. Got my ST170 recently, picked up an OEM sub off of ebay and put in a 30amp fuse in spot 24. Sub not working!!! So pulled out the stereo (after market Sony unit with sub output) and found the Amp Remote wire (blue one) is not connected to anything. Do i need to tap this into another wire or am i missing something else?

Any advice will be great, cheers, Rich.