remote power adapter

I am installing an amplifier and subwoofer into a 2007 Infiniti G35x. The Infiniti has an existing Bose System. What I did was, i probed the Bose Amps wiring harness and found the turn on lead. I tried to tap the turn on lead to a Relay to turn on my other Amp. The Alpine Amp and Alpine sub are functioning correctly. but when the turn on wire from the Bose amp is tapped, the voltage drops to 3.5 volts and fails to turn on both amps. When i disconnect the wire i tapped from the Relay, the Bose turn on lead jumps back to 12 volts. After i encountered that problem, i tried to duplicate a method that this setup had in the owners previous car. He has this thing called a "Remote Power Adapter." Now, it has four wires. [Grey]. I remembered the Red went to a 12v Source, but i am unsure about the other colors. I assume that blue goes to the remote and i remember it being wired to the speaker wires. I think when the speakers received a signal from the head unit, the Adapter relayed a 12v source to the remote lead. If you need more info, please ask.

If you could explain the voltage drop or the Remote Power Adapter, that would be a great help.

PS. i did not attempt to go behind the radio because these cars are starting to look like space ships and i have no intention on making such an effort.

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Proudly stuffing large packages into small boxes since 1983.

"It Has Four Wires, Red, Black, Blue, Grey"

*Correction.

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Proudly stuffing large packages into small boxes since 1983.