Review on Metra 70-1857 Tuner Relocation and Bose Integration Harness: Superior GM Vehicle Upgrade by Carl Watkins

Perfect suspension but if you use it on old Cadillacs with factory Bose (where each speaker has its own built in amplifier) you will get noise when you turn the car on. The first step is to buy 2 ground loop isolators. This takes care of the "pop" between tracks or switching stations. Next thing you need to do is do a little rewiring in the trunk where this makes a connection. Note. If you're not an installer, this doesn't make sense. The problem is cod when you turn on the radio. So you need to use the red wire in the trunk (on that harness to turn on the amp), that's the blue wire on the harness. The blue wire coming from the main unit should still drive the power antenna but should also drive the 2 relays. The 2 relays must share one of the speaker wires on the rear speakers. For example. 85 goes to ground 86 goes to the remote wire from the deck 87 goes to the speaker and 30 goes to the amp side of the speaker (essentially you disconnect the speaker wire until the radio turns on. The blue wire then activates the relay to turn the speakers on. Basically taken after the "pop" it's a temporary thing and the only solution other than rewiring the entire machine. Now I know it doesn't make much sense, but it will if you're an installer. You will understand point.