Musicbox stuff: relay, capacitor, amps

For my musicbox mobile mp3 player, I needed a way to turn it on automatically when the car turns on.  That meant I needed a relay.  I bought one from for 29 cents and installed it inside a little Radio Shack project box.  I also had a problem with my musicbox: if you turned the system on in the car without actually starting the engine, and then once it was playing, you started the engine, it would reboot.  So I installed a giant capacitor in hopes that it would fix that, but it didn't.  Oh well.  In the process of installing the cap, I had to move my amps around on the board they're mounted to, so I included some photos of that at the end.

This is the relay itself, it's tiny, only about an inch tall. photo courtesy of

the blue wires are for the 12V control signal; when applied, that signal shorts the red wires to provide the high-current source to the system.

it's really hard to solder wires that big when they're bent and you only have 2 hands. cable ties made it possible.

and without the cable ties, the solder joints would almost certainly break because of the pressure from the wires pulling away.

a 1 farad capacitor... still doesn't provide enough capacitance to hold the voltage at 12V during ignition, unfortunately.

I mounted the cap label-down because it looks a lot cooler than that cheesy label.