12v tap through firewall?

[insighttex]

Hi all -- first of all thanks so much for all the posts here. I just got a 2010 EX without Nav on Dec. 31st '10! Love the car and I've used the info here for swapping out the 4 factory door speakers as well as admiring a lot of the mods. Great stuff!

So I have a powered sub that just got here today and wiring kit. I am searching here and the web for some info on best spot to get through the firewall for the 12v tap but no luck so far. I would really like to not run it out the driver's door... can anybody toss me a bone for tips on passing the cable through the firewall to the battery?

Also, does the EX radio have an extra set of RCA's to feed the sub? The sticky on how to remove the radio was very helpful but it was for the LX... any details there would be much appreciated as well. edit: just found that there are no RCA's... hmm do I have any options while keeping the oem unit?

thanks so much!

[JimJohnD]

I ran my 12v line across the front to the passenger side. There is a large rubber plug in the firewall where a wiring harness passes through. I carefully made a small cut in it to pass my power and ground wires through. Then resealed with silicone. It comes out just behind the glove-box. I then took it all the way back to the hatch area under the side trim. Defiantly a two person job to get the wire pulled through. I used the JL Audio wiring kit. The positive was long enough but the ground wire needed an extension to get all the way to the hatch area. Don't forget fuses. I have one at the battery and one on each amp.

You can get speaker-to-line level adapters for about $30.00. I'm using a Rockford 3Sixty.2 processor and it performs the same job and more. Many of the newer amps can also use speaker-level inputs.

From the passenger area everything looks OEM, except for the little JL badges I added to the corner of the speaker grills I've had my I2 for about a year and a half and I couldn't be happier.

[SkyBlu]

There are two places you can run your wires thru the firewall. One on the driver side and one on the passenger side. I found that the driver side location is easier because it's higher...better reach..after the airbox is removed for access. I used one of those electrical wire threader thingy...not sure what the name... but it's basically a flexible steel cable for threading electrical wires thru tight space. I bought it at Home Depot for $10.
As far as grounding location for your powered sub... there's no need to run the ground cable all the way to the battery. The ground cable can be grounded anywhere! You just have to ground it to the chassis of the car. That's the reason why all amp wiring kit..the ground cable is only 4 ft long. I grounded mine to the car chassis next to the spare tire. I'll see if I can take some photos of it.
In regards to the head unit...it's not bad quality but I think a small investment in an aftermarket unit will give you much better sound quality. The factory head unit is not designed to handle higher power speaker and subs. If you are changing out the speaker and adding sub....then adding an aftermarket head unit is the way to go. I bought my Sony head unit for $100 including two speakers. The Sony head unit also have aux and USB inputs, RCA outputs..etc. I can load mp3 on a usb flashdrive and play my music with it.

[nwwoods]

I used one of those electrical wire threader thingy...not sure what the name... but it's basically a flexible steel cable for threading electrical wires thru tight space. I bought it at Home Depot for $10.

It's called a Fish Tape. Indispensable for home wiring. For automobile applications you may want to consider a Fish Rod or a Glow Rod as well, also available at home improvement centers. A "rod" is thinner and more flexible for dealing with all the curves and tight spaces.