This isnt exactly third gen specific, wiring a sub/amp in my friends 2002 saturn. His stock head unit does not have a wire available to control the amp. So I need to know if I can splice the control wire into any switched 12V source such as the switched wire that runs into the back of the stock head unit.

 

As long as it's controlled by the head unit and not keyed ignition, yes. If there is a power antenna lead off the back of the radio, sometimes that's a good source but some newer decks cut power to the antenna when CD or TAPE is selected. Just probe with a meter or test light and find a source that has 12V when the radio is on.

 

There is no power antenna wire or anything leaving the head unit that I can use. But the orange wire that is the switched 12V source for the radio should have the same effect right? 12v when the igniton is on and the radio is on. and no juice when the ignition is off.

 

Using the orange wire will turn on the amp any time the key is on, no matter if the radio is on or not.

 

If you are set on using the stock head unit, then what I would suggest is running power from a constant source, i.e. directly from the battery, to a switch inside the vehicle. That way the amp can be turned off when the radio is not in use, instead of having it always on when the car is on. I would also suggest using a switch with a light in it, that will help keep him from leaving it on when the car is turned off.

Or you could just go on craigslist and find an aftermarket head unit that will provide better options. Hell, for $70 you can get a Pioneer head unit brand new from Best Buy, or for $40 you can get a Dual Electronics one that would be better than trying to use something that's not meant to be used with your factory equipment. Just my $0.02

EDIT: But to answer your question directly, yes, you can run it to a 12v accessory wire, but that will turn the amp on any time the car is on, regardless of whether the radio is on or not. However, turning things on unnecessarily will cause them the wear out prematurely. Just a thought.

 

Ya I know it doesnt make a lot of sense to do it this way. We both work at walmart so a 70 dollar head unit is...well a lot more money than it sounds like. I like the idea of a switch though, that would probably work quite well.

 

ebay you can get top of the line refurbs for cheap. factory fixed unit.

any Pioneer DEH-[some random numbers]

will be a good choice. Great units.

 

I hear ya. My suggestion then would be to go with the switch, then save up a little and pick up a new head unit down the road. Either way, I wish you the best of luck!

 

Don't wire the amp switch directly to the battery. Use a 12v ignition switched source.

You think you will remember to turn off the amp every time, but I promise that you will forget, and then you'll be stranded with a dead battery.

 

That's a good point. Personally, I generally like to have the option of turning things on no matter if the car is on or not, but I'm also paranoid about dead batteries... However, it would probably be wiser to run it from a switched source to a switch in the car, to the amp.

Still.... I wouldn't

 

hook it to the parking lamps in the rear, ya know the position before the headlights come on.

Should turn those on any time you drive just for safety.

 

Not sure I'd do that...

 

BAD IDEA. You will forget.

 

LOL I had quite a few things wired directly from the battery with a switch on my last two trucks, never forgot to turn them off. Just gotta pay a little bit of attention is all.