Pioneer FHX820BS HU, Sound ordinance 4050 50 x 4, two sets of Polk component speakers(1 pair front n other in both sides rear, 12" Polk sub in enclosure with mono amp. Installed steering column controller. HU grounded into firewall, 4 speaker amp ground under passenger seat, mono sub amp in back grounded to floor. Rca to both amps separately. Power cords on left side of car and three sets of rca cables from head unit to amps on the other side. All grounded separate locations on sanded metal floor. Getting tic static from second pair of speakers when rca's are plugged in. Whenever i plug them in, it does not make a difference which one goes first, the second RCAs causing problems that sound like a ground loop from what I have read. REALLY NEED HELP! Are the places I grounded to good enough? Is the floor a good grounding location in a Sienna Van? Does this head unit come with known issues? Thisis all in a 2009 Sienna.

 

It sounds like you have unplugged/plugged in the RCAs while the headunit was turned on. With a Pioneer, you have almost certainly damaged the pico fuse inside of it. It will either need repair or you may get lucky by grounding the RCA shield at the headunit.