hey guys, i did a quick install into a mates pulsar he has a response QM-3788. it has a sub out lead. but the only plugs to plug the rca leads into are the sub out and the 4 leads hanging off 2x (something) left. and 2x (something) right. pluging them into sub out did SFA. so i plug them into the 2x lefts it plays at low volume, turn it up slightly and the subs just go into a fit like GGGGGRRRRRRRRRRRRRRR untill its switched off, i tries right, left and 1 from both. all the same probs... what am i doing wrong? this sub out plug have anything to do with it?

Sub out is made for sub out, plug the rcas into that. If it didn't make any noise then there is likely a menu on the head unit that has sub out turned off.