View Full Version : Adding Aftermarket amp and sub, cant find 12 volt acc wire

06-17-12, 12:05 PM
Ive followed all wire diagrams i can find, and ive pricked and tested every wire going into the bose amp in the trunk, but i can not find a 12 volt acc wire, iv found plenty of 6 volt and some 7 volt. Ive also went behind the base cd player and nope, no 12 volt switched acc wire their either. Is it even possible to simply add a sub to the existing system? I love the way the existing bose sounds, i just want more punch on the bottom end.

06-17-12, 12:21 PM
Are you looking for a wire to tap into for the remote turn on for the amp? If so, use the ignition fuse, just shove the remote wire into the cold side of the fuse's spot and push the fuse down over it...otherwise look into an AudioControl line out converter, one of their models includes a remote turn on.

06-17-12, 10:21 PM
Thanks, thats what ill do until i do further upgrades.. its dirty, but gets the job done

06-17-12, 11:58 PM
Are you looking for a wire to tap into for the remote turn on for the amp? If so, use the ignition fuse, just shove the remote wire into the cold side of the fuse's spot and push the fuse down over it...otherwise look into an AudioControl line out converter, one of their models includes a remote turn on.
With all due respect, that is terrible advice. When did pushing a fuse down over a wire ever become remotely acceptable? Perhaps you do this with your own car, but this is far from sound advice. You shouldn't advise other clearly impressionable members to use such wreckless techniques.

06-18-12, 12:22 AM
With all due respect I offered a quick suggestion as well as a very clean suggestion in the AudioControl device...either one gets the job done, the OP has the choice to do whatever they want, I just offered a couple possible solutions.


06-18-12, 12:48 AM
So here are some of the numerous problems with your wire/fuse suggestion...

Inserting a wire into this space carries a high risk of breaking off wire strands when the fuse is inserted. This may may result in these strands shorting with other circuits.
Inserting a wire into this space increases the physical size of the cavity beyond what it was designed for. This will usually deform the female contact in the fuse block (causing permanent damage and a possibly expensive repair). When the wire is eventually removed and wired correctly, there is a high probability of a poor or intermittent contact between the fuse and female terminal in the fuse block.
Once the female terminal contacts are enlarged beyond design, the engineered surface pressure between the female terminal and the fuse will be much less and can reduce the current carrying capacity of the circuit. This may lead to increased heat (poor connections = heat production) and depending on current flow within the circuit, can lead to risk of fire.
There is a risk of the wire becoming dislodged while driving. If the IGN circuit becomes open it may cause unpredictible results and/or cause the car to shut down. Not something I'd like on the freeway or when turning left across oncoming traffic.

When you're going to offer possible solutions you should have a better understanding of how bad suggestions can cause things to go terribly wrong. No matter how you slice this, it's just wrong and I hope the OP doesn't carry through with it.

06-18-12, 04:15 AM
I understand all thoses risks.. do u know of the location where i can tap into 12 volt accessorie switched power? Or is getting the $100 loc the only option?

06-18-12, 11:32 PM
The "problem" with these cars (and this is relative to what you're doing), is that the amp and other modules are now switched by data signals. Older vehicles would use an amp turn-on wire but now, the radio simply sends a data bus signal to the amp instructing it to power on. I'm not aware of a single module in these cars (roughly 25 depending on how well optioned your vehicle is) that isn't connected directly to battery positive voltage at all times. Power modes dictate how the module will behave and "sleep". For purposes here, the radio and amp are considered modules. Both communicate on the data bus and behave based on data messages they receive. You may notice when you turn up your volume, the amp doesn't respond immediately. This is because the audio from the radio remains constant but it sends a data message to the amp which responds by increasing the audio output.

It's been a while since I went through the schematics, but I think IGN voltage is about all you're going to find as a hardwired signal. ACCY, if I'm not mistaken, is all handled by data bus messages. I'm thinking this will mean your amp will only power on when your car is on, not when in ACCY mode (but this may not be a problem for you). A module might be a better way to go. If you decide to wire it to the IGN signal, my recommendation is to splice to the existing circuit using a soldered connection and insluated with heat shrink tubing (I personally don't support using Scotchlok's or similar products). Given this is only a switching signal, you should be okay to tie in after the fuse and use the protection of the one GM has installed (do not increase the rating of the fuse GM installed as this may cause other problems). If you were to tie in before the fuse (hot side), you would need to add a fuse of your own as close the the fuse block as possible. Fuse size depends on your amp but in most applications like this only requires a 1A - 2A fuse. Contacting the amp manufacturer or product technical reference is your best source for this.

06-19-12, 12:56 AM
Explains alot

06-19-12, 09:53 AM
"Jamming" a wire into a fuse holder should Only be done while wearing a Bloody Apron with a Cleaver in your other hand ;)

It's Butchers work...

If you want to do it right, you need to use a 12v Ign source to energize an added relay to power-up the amp. There are Very Few places you can find that Ign source. I went to 12volt.com (a Stereo & aftermarket Installers site) and was given this when I did it on my car several years ago.

Accessory wiring

Behind the glovebox is the Instrument Panel Module. There is a 26 pin plug in which you'll see a small pink wire at pin 6 (reads as ignition). Or, for accessory, the 24 pin plug at position 7. You can't load these circuits so use it to drive a relay which feeds your circuits. Rear outlet 20A feed located under tunnel carpet above drivers rt ankle. Blue connector, pin 1, Red w/wt- stripe.

06-19-12, 11:10 PM
In this case I don't think it is a problem to connect the amp directly to the appropriate circuit. In fact, a relay may even draw more current (typically around 200mA for the coil). The amp turn-on line only monitors for the presence of 12V. When it sees this, the logic in the amp will cause it to power up but none of the required power for the amp to function is derived from the amp turn-on signal. This line is strictly for signally and therefore very low current. This is no different than an "Ignition Sense" line on a cell phone car kit or two-way radio.

06-20-12, 09:54 AM
What I wanted was to "create" a keyed accessory power point for Everything I might want to add (Radar, Laser Jammer, etc.) for then, and in the future. I actually used a reed relay connected to that source, and then the output from the reed to energize the coil on the Bosch 30A relay...

Whatever you do, you want to be aware of the sensitivity of the electrical system ;)

06-20-12, 11:43 PM
That's the pink jewel. Anything more than a radar detector is too much for it.

DD correctly points out this cars differences from most of the cars on the road. For a quality result, use a relay controlling a properly fused direct-to-the-battery source.

05-31-14, 08:58 PM
You guys saved me some headache.... I was installing a TranzIt BLU HF module and could not find switched 12V to save my life. For now the unit is powered off of the heated seat fuse (+ its own in line fuse(2A)) which powers on once the car starts. Now to figure out how in the world to get this to power up in "accessory".

Thanks again guys