Alternate source for 12v power
 

Running an amp this weekend, and probably putting it under the passenger seat. Are there any nearby sources of 12v power to tap into, that turn on and off with the car? The one behind the head unit is already tapped twice, and I would prefer a fresh source.

any amp will likely draw more current than any existing wire can supply to it along with whatever is already there. Run new power wire with proper gauging and fuse directly from the battery. This is a safe way to do it and not at all difficult in the z..do a search. As for remote turn on or accessory power(which don't see how you would need this)... Remote should be off the head unit or lead wire from the Bose amp

I am running an 8 gauge power wire from the battery, but I need a place to tap into for a 12 V remote turn-on input. I know I can use the one connected to the head unit, but I am already tapped into that one for my steering wheel control also.

I would rather find another line closer to the passenger seat to use, that turns on and off with the car. Bigaudio, do you mean the one under the glove box?

ok, that just confused me more lol. What is a relay? What does 86,87, 85 etc.. stand for? I have never used a relay before. is there just a single wire I can patch into?

ok. I am also adding an amplified sub in a little while. will I need another relay for that or will one relay supply multiple amplifiers?

what about if I run it off of the power outlet? Is it the one connected to the cigarette lighter plug under the glove?

Oh damn. Didn't want to start a war guys. Just trying to get my amp wired up.

:ugh2:

Agreed with Italy about the relay and its importance when multiple devices are being turned on and don't forget to fuse the relay too while were at it. It is absolutely the right way to do it. That said it does not mean that you cannot get away with using existing remote trigger. What is important is knowing the draw will match what is available. To be safe, a relay will remove any guess work and another benefit is that you can delay turn on and turn off to prevent power spike heard through the speakers. What is confusing is why would the op use accessory power to trigger the amp. By that rationale, every time your car is on, the amp is on irrelevant whether the head unit is on. If this is the case, having the amp in full power mode before other equipment in the chain turned on will cause damage to the system eventually...now I'll sit back and enjoy the fireworks..;-)

ok, so I can either:

1. Use the remote amp turn on wire on my aftermarket headunit.

2. tap into the power outlet wire, but this will turn it on whenever the car starts regardless of whether the radio is on. This may also cause damage eventually.

3. Use a relay which is connected to the 12v wire that my HU uses.

4. connect a turbine and wiring harness to a small hamster wheel inhabited by hamsters that only run while music is playing.

Pretty much cover it?

So if I have 2 amps, which I eventually will, plus the steering wheel adapter all connected to the remote amp turn on wire behind my aftermarket head unit (blue and white), this is will work? Not saying it is the right way, but...

I agree, if you have a REM output on your head unit "Blue/white" that to is an option as it was made to turn on amp(s).

You should not have the steering wheel controls connected to the REM output wire. If you are thinking the red wire is also the amp turn on wire that is incorrect. The blue/white wire should not have anything wired to it right now. Do you have a picture of how you wired your head unit?

JVC Mobile Entertainment \ KW-R900BT - KW-R900BT

That links to the head unit install PDF. Right now I have the blue and white connected to the blue and blue/white cables of the aftermarket harness, as it said to do in the instructions.

For some reason I thought it was connected to the Metra Axxess unit, but it isnt.

The blue wire on the metra harness is only if you have a factory amp, so you do not need that wire unless you have the bose system.

so the blue and blue/white wires on the metra harness don't need to be connected to the head unit blue/white wire? Is the Blue/white wire on the head unit harness only to be hooked up to a REM amp wire?

If so, I will just use that, and worry about the powered woofer when I get it.

The blue wire on the metra as I said, only needs to be used if you have a factory amp "you do not" so yo can omit that wire and use the blue/white wire for your amp.

Figured this would be a good thread to run off of. Basically same question " I am looking for an alternate source for 12v power".

I am looking for a solid 12v constant to tap my CarPC into. I was going to run off my Pioneer HU existing 12v constant and switched, but think that I would be maxing out that line and may not be smart. I want a clean 12V constant source without having to tap right from battery.

Off hand, is the cigarette lighter a 12v constant source? Also, for the 12v switched, would it be okay to run off of the HU or would there be a better source for both?

The 12 volt power plug is one option. However if you need a clean and strong power source fuse and run a 14 gauge wire from your battery, and if you need a switched source setup a basic relay and a fused line from your battery.

Hmm sounds like that may be the best option then. (running from the battery. I will have to look into options for that.

For the constant 12v w/ 14ga wire from battery- 10A inline fuse sufficient?
http://www.radioshack.com/product/in...tent=CT2032234

Match your fuse to what your device needs.

Oh gosh now were getting beyond my auto electronic knowledge. :eekdance: Looking into it I think a 20amp inline fuse close to the battery may be sufficient.

My device is a CarPC running a Mini-Box M2 ATX 160w power Supply

Smart Car PC Power Supply
- 160 watts output
- Ideal car Power supply for operating Core 2 duo, Celeron, AMD systems
- ATX, 6-24V wide input range
- Intelligent shutdown controller
- ON/OFF motherboard control
- Survives vehicle engine cranks
- Battery deep discharge prevention
- High efficiency, 160 watts output
- "Anti-Thump" Amplifier remote control - 15A automotive fuse (mini-blade)
- VIA, P4 and AMD CPU support
- manufactured by mini-box.com
- ROHS compliant version

So in retrospect, I will be running 2 power wires, from the battery, one for constant and one for switched. On the switched I will use a relay.

Match the fuse rating on your power supply.

Yessir,

Going to pick up an inline 15amp fuse today and some 10-14 ga wire. Hopefully get this puppy wired in tonight and will document how it goes in a new thread. Thanks Big per usual. :tiphat: