today i installed a PAC LOC that has a level ****, i installed it in the arm rest for comfort.

PIC

however when i set the level to the max on the LOC and the Amp i get a signal but its very low, but when i unplug one of the RCA's from the amp the level goes up(the way its supposed to be). I taped both the rear left and right speakers for the LOC(i want to get a stereo signal and not just from one side). Can some one give me an idea of why its acting up this way,