Guitar electrics (for guitar geeks)

[[Shizo]]

I opened my Stratocaster's (copy) front plate and found a yellow wire running to the back, and at that end connected to the bridge (and therefore the strings). I can only guess it's for grounding? I accidentally broke it off the front plate, but I'm not sure if it's important. The guitar still works fine.

I also want to install an LED that would turn on when the guitar is plugged in. I have an LED, but it doesn't seem to work with AA/AAA 1.5v batteries. But it does work with a 5v electric adapter. My questions are:
- Would it work with a 9v battery?
- Is the current on the guitar pickups high enough to light up an LED? With a weaker LED, for example from a small mp3 player. It would be much better!

I'm open to any suggestions on my little project.

 

[ralpheo]

Been up all night with this one ,huh?
Yes, any wire that goes directly from a pickup or electronics to the bridge is a ground.
Here's the thing. LEDs are very sensitive to voltage. Too little,they don't work, too much and they'll pop like a balloon. If 5 volts lights it up bright, then that's all you need-- 9v will burn it out. If it's not so bright, try the 9, but only for a few seconds!
Fortunately, Radio Shack still sells the little holders for batteries. If you can find one for AA or AAA, get that. Each battery is 1.5v, with four you get 6 volts, which is what the power rating on the led is, most likely.
About the only way to get small electronics parts these days is through the internet and the ads in the back of mags like Pop Science. Good luck with your project.

 

[[Shizo]]

Look at my location. For me it's evening. And no Radio Shack here.

Thanks for the info! I didn't know you could stack up the batteries like that. I just tried it with two AA batteries (3v) and it worked. But this way, I would have to come up with some switching mechanism, which would turn on the light when the plug is inserted.
Is there any voltage at all in the guitar's audio cable? If there was, it would be much easier to make LED work from the external power in audio cable.