ok, i got it figured out. i bought a new kenwood head unit to replace the car stereo. as i was wiring it up, i saw that the old one had a wire connected to the 12v signal that turns on an auxiliary amplifier. but....there was no amplifier to be found. the wire was blue with a white stripe. i looked at the relays that trigger the speakers and walla, it was the same wire. the default position is that the home theatre has the speakers. when you turn the car stereo on, the 12v that is used to turn on an aux amp is energized and it clicks the 2 speaker relays and the car stereo now has the speakers.
that said, i still dont know what the 120v relay is for.....
one thing at a time. it is nice to have a car stereo with bluetooth and streaming audio from my phone built it.
later
tom
|