Okay, I started a new thread for this, not to clutter up the forums but to keep the old flames in that thread.

I'm going to install some neon lights in my car, and I was wondering if I could tap into the power / ground wires from the wires going to my headunit.

This might seem like a simple question, and I know the answer is probably yes, but the reason is that I already have my new headunit, and my harman kardon drive + play, and I would want to add around 2-3 more neon lights. I could run it to my battery I suppose, but running it to the wires behind my headunit would be much more convenient.

Is there a max power I can draw from them or anything?

 

How many neon lights ? 2 or 3 should be ok. You might cause noise in the stereo from the neon lights getting there power from the same wire. Have you checked out LED lights? They look a lot better, You should think about going that way.

 

I'm assuming you're looking at interior lights. In that case the answer to your question depends on whether you're running any speakers from the head unit internal amp. Although to be honest, if you want a simple solution, I would just splice the wires for your lights into the cigarette lighter. It has a decent amount of amps and constant voltage.

 

I tapped in the "Always On" 12V Head Unit wire for my Sirius radio and separate FM Modulator. And I used a Dash mount bolt just behind the Unit for a ground. Everything has been working fine.

 

Yes the cig. lighter is a keyed hot on our cars and would be a better choice than the head unit wiring.
Neon can draw a decent amount of amps.
If you go wit LEDs it doesn't matter as much as the amp draw is very low.
Hope this helps.

 

if they are interior, you're fine on the radio.

if it is an underbody kit for outside the car, wire a switch and go direct to the battery, those can short out real easily.