Power-handling capacity of pre-existing power wire for factory sub?

[Jeff S 2]

Reading through the archives, I've gotten the impression that there's a set of +12v and ground power wires that might be suitable for driving a sub amp already present inside the passenger compartment behind the front passenger's kick panel (normally used to power the OEM sub's amp). Does anybody know whether these power wires still exist in the 2008 SportTrac, whether they exist in ALL models, or only ones that already have the "audiophile" system installed, and how many amperes of power they can reliably/safely/officially deliver?



Also, if everyone who posted suggestions for sub+amp combos yesterday before the board's crash could repost them here, I'd really appreciate it

 

[Dingo]

I recommend that you run a proper power wire.

 

[Mike Caldwell]

I know in my '02 the wiring for the factory sub was tiny, wouldn't really trust it to handle the power of an after-market sub. It is really easy to run new wires, I having never done it before took it to a buddy and we both did it, I just owe him a case of cheap beer.

 

[Jeff S 2]

Any idea what gauge the pre-existing wire is, or the amperage of the fuse that protects it? I know that amps need lots of amperes (sorry, bad pun), but I also know that the prevailing practice (in Miami, at least) of routinely using AWG4-8 wire for amp installs is usually gross overkill for the way amplified subs actually get used in real-world applications augmenting factory head units. Even if the sub's amp can deliver 100W RMS, the likelihood of it ever actually DOING it for any meaningful length of time when it's augmenting a factory head unit that *might* be capable of 5W(RMS) per channel on a good day is pretty remote. Worst-case, I can throw a supercapacitor in parallel with the amp on the "amp" side of the wires to ensure that on those rare occasions when it needs to draw more than a few amperes for more than a few milliseconds, it can get the extra current it needs from the capacitor instead.

 

[Dingo]

Jeff, I don't mean this to come out mean or belittling, but if you have to ask us about what's in the truck, you probably shouldn't be even remotely attempting what you're trying to do. On the second gen trucks, it's so incredibly easy to run the wire, anyway. I actually ran mine outside the truck, and not under the vinyl floor. If you try to use a capacitor, you'll have to wire a resistor inline with it to keep from blowing fuses or burning up the wiring on your new truck. Once that resistor is there, the capacitor won't recharge fast enough to work efficiently, and the resistor will get hot enough to melt your interior.



If you need any suggestions on how to hook up your stuff, let me/us know. We're pretty helpful folks. I'm actually adding another amp to mine this week.

 

[Jacob Dryer]

On top of what Dingo said about the capacitor, it will also be cheaper to just run the correct gauge wire and not use a capacitor.

 

[Jeff S 2]

Hmmm. Maybe I HAVE been trying just a little too hard to avoid running a new wire at all costs



I'm actually kind of frustrated at the moment. I tried buying the (alleged) SportTrac installation guide from Scosche, only to discover that they don't actually HAVE a guide specifically for the 2008 SportTrac. Or even the 2007, for that matter. The closest they have is 2001-2004. If you go to schsche.com and search their installation guides, it LOOKS like they have one for 2008 SportTracs... but after you pay, log in, and try to download it, you get a vague "file not found" error message with instructions to call them for assistance. It turns out, the file wasn't found because it doesn't even exist. *******s. I can't believe it's even LEGAL to do crap like that. Of course, they'll probably claim I was merely buying 30 days' access to their online library instead of buying the guide to a specific vehicle, but if they give me the *slightest* attitude, they're going to be staring at a chargeback come Friday morning :angry:



So... what would I be getting myself into if I decided to run proper wires? The one line I absolutely won't cross is drilling a hole through the firewall, because there are too many things that can go wrong and cause expensive damage if I screw up (not to mention, on my old car, there were some pretty scary warnings in the Scosche guide about the danger of accidentally triggering airbag deployment by drilling through one of its sensors... with potentially fatal consequences if you were upside-down laying on the driver's seat with your head below the steering wheel, and the airbag hit your chin and broke your neck)...

 

[Dingo]

I ran mine straight down from the battery, through the frame to the back of the cab, and then out and up.

 

[Jacob Dryer]

and if you don't like Dingo's answer there is almost always a rubber gromet that can be sliced and the wire fed through it without drilling any new holes. That is what I did on my 02, I'm not certain what is under the dash on a 07-08 but there has to be someplace to feed it without drilling.