Looking for some help, I just installed a HOG TUNES amp on my 2011 CVO roadglide, this is going to be wired to power two speakers in my lower fairing. I taped into the four unused pins on the ultra harness that are labeled Rear speakers at the back of the radio. Problem is I don't have any sound coming from those pins, does anyone know if there is a flash to turn on the rear speaker outputs? The factory front and rear speakers are all being powered via the HK AMP and getting there signal from the front speaker output as far as I can tell. Any help is greatly appreciated...