Relay Instead of DPDT Switch?

For some reason my brain won't wrap around this application. I wired into a GM head unit to tap into the CD player input in order to run a MP3 player or ipod. I was going to just wire a mini DPDT switch to change the input from the normal CD player input to the MP3 input that goes to a 3.5mm jack. I was hoping someone here could help me diagram a relay to switch the input depending on which one had a signal. Is this easy or hard to do? Thanks for any help.

Most are Grounded so it is easy. You must mount into a Metal Grounded Box to eliminate humm and Motor noise.John DeRosa (Hotwaterwizard)

Stockton California

When in doubt, try it out !

The above is best but if you want to use a relay, you need a voltage output from either iPod or MP3 and good luck with that! The voltage output, probably 5 volts will trigger a DPDT relay with a 5 volt coil.

I already wired the switch but thanks for this. I don't think I'd be able to get a trigger from either input.

Yes it means opening one up and bench testing, best of luck on opening one of them.

I use an Audio Switcher on my amp because it does not have a aux power wire. It detects the audio signal input and provides 12v output to switch my amp on and off.John DeRosa (Hotwaterwizard)

Stockton California

When in doubt, try it out !