View Full Version : tC firewall gromet question. running power wire


brian
03-01-2005, 11:27 PM
Hey guys, trying to install a sub, amp, and headunit all at the same time. I'm looking at running the power cable through the firewall right now and I've read a lot everywhere that it's on the drivers side. I looked there earlier and saw this, is this the right gromet I'm supposed to run it through? I snapped a quick pic to ask you guys.

http://www.brianyau.net/IMG_3003.jpg

tCshamgar
03-01-2005, 11:44 PM
Whatever you do make sure you run the RCA cables and your Power wire separate... like with at least 6" of distance between them. Running them close will cause electrical noise in the RCA's --- translates to a humming sound in your amplified speakers when the engine is running.

ScionTCTrav
03-01-2005, 11:48 PM
Whatever you do make sure you run the RCA cables and your Power wire separate... like with at least 6" of distance between them. Running them close will cause electrical noise in the RCA's --- translates to a humming sound in your amplified speakers when the engine is running.

Hmm Really? I didnt know that..Mine are ran together..Is there anyway to test this?

jaydub
03-01-2005, 11:52 PM
Whatever you do make sure you run the RCA cables and your Power wire separate... like with at least 6" of distance between them. Running them close will cause electrical noise in the RCA's --- translates to a humming sound in your amplified speakers when the engine is running.

Hmm Really? I didnt know that..Mine are ran together..Is there anyway to test this?
You'd be able to hear it if you were getting any interference. It's the most frustrating noise in car audio. :)

k_splay
03-02-2005, 12:13 AM
Hey guys, trying to install a sub, amp, and headunit all at the same time. I'm looking at running the power cable through the firewall right now and I've read a lot everywhere that it's on the drivers side. I looked there earlier and saw this, is this the right gromet I'm supposed to run it through? I snapped a quick pic to ask you guys.

http://www.brianyau.net/IMG_3003.jpg

wow, I was just wondering the EXACT same thing!! But, I'm installing fog lights.

After investigating that grommet.. there's a 'tunnel', about the size of a ball point pen, that is on the left side of it with a bubble on the engine side of the wall. I'm thinking we can simply cut the bubble and have a clear tunnel through the grommet.. otherwise, the grommet's rubber in that picture are taped down to the bundle of wires..

Also waiting for responses...

-K

retrodrive
03-02-2005, 12:57 AM
You can run RCA's with power cables if both have descent insulation. ____ty RCA's will have noise interference sometimes if run next to power.

Now look on the left side of that bigass grommet. See the ovalish cutout in the white carpet padding? Take it out and drill right through the metal in that spot. It is specifically designed for that. Don't touch the stock gromet.

I am almost done with wiring for my entry competition setup and I will share pics soon enough. TC is an custom audio installer's paradize.

brian
03-02-2005, 01:38 AM
You can run RCA's with power cables if both have descent insulation. ____ty RCA's will have noise interference sometimes if run next to power.

Now look on the left side of that bigass grommet. See the ovalish cutout in the white carpet padding? Take it out and drill right through the metal in that spot. It is specifically designed for that. Don't touch the stock gromet.

I am almost done with wiring for my entry competition setup and I will share pics soon enough. TC is an custom audio installer's paradize.
under the carpet? i don't see where you're talking about, sorry.

f00dstamps
03-02-2005, 01:47 AM
i ran some wires through the firewall on my gf's TC. there is a smaller grommet that should do the trick and it is very easy to reach. the hole might be a little bit too small if you run too large of a guage power wire.

it's near the big grommet there that you have taken a picture of. my best explanation of how to locate this grommet is: while you're on the driver's side fender, reach along the firewall and run your hand towards the outside of the car alongside the firewall. the grommet is located behind the wheelwell on the firewall on the driver's side. i'm sorry if this is confusing but i think you get the point.

i also suggest that you run the power and low-level (RCA) wires separately. when that low-level signal gets amplified to a high-level signal, that noise is also going to be amplified. run the power wire along the driver's side door sill and run the RCA either down the middle of the car or along the passenger side door sill. high quality, well-insulated RCA's would be the way to go too. get the ones that are designed for mobile electronics instead of home audio.

brian
03-02-2005, 04:46 AM
i ran some wires through the firewall on my gf's TC. there is a smaller grommet that should do the trick and it is very easy to reach. the hole might be a little bit too small if you run too large of a guage power wire.

it's near the big grommet there that you have taken a picture of. my best explanation of how to locate this grommet is: while you're on the driver's side fender, reach along the firewall and run your hand towards the outside of the car alongside the firewall. the grommet is located behind the wheelwell on the firewall on the driver's side. i'm sorry if this is confusing but i think you get the point.

i also suggest that you run the power and low-level (RCA) wires separately. when that low-level signal gets amplified to a high-level signal, that noise is also going to be amplified. run the power wire along the driver's side door sill and run the RCA either down the middle of the car or along the passenger side door sill. high quality, well-insulated RCA's would be the way to go too. get the ones that are designed for mobile electronics instead of home audio.
I'm going to be running a 4ga, I'll look for this smaller one tomorrow and see if it's easy access. I'm new to all this and this will be my first install so I just don't want to f anything up.

f00dstamps
03-02-2005, 05:19 AM
if you're trying to go through the large grommet pictured there, understand that it is a tight fit. most likely, you'll have to poke or cut a hole. be very careful so that you do not cut or pierce any other wiring. if you do that and be patient, you'll be just fine.

indianenvasion
03-02-2005, 05:40 AM
i think you should cut the hole and use some sort of plug to hold the new power wire in place nice and tight.

erazboy
03-02-2005, 07:59 AM
i ran my 4ga throught he grommet on the passenger side of the firewall. it comes through behind the glovebox

brian
03-02-2005, 08:08 AM
I really don't feel like drilling if I don't have to. I'm thinking of just trying to get it through that gromet pictured, or would going through the passenger side like erazboy did work better? I was just thinking since the battery is on the driver side it'd be easier to just run it from that side so it'd be closer.

erazboy
03-02-2005, 08:16 AM
i got my info from here
http://www.yoursciontc.com/forums/index.php?showtopic=795&hl=grommet&st=0
and
http://clubsciontc.com/modules.php?name=Forums&file=./viewtopic&t=2001

erazboy
03-02-2005, 08:31 AM
I really don't feel like drilling if I don't have to. I'm thinking of just trying to get it through that gromet pictured, or would going through the passenger side like erazboy did work better? I was just thinking since the battery is on the driver side it'd be easier to just run it from that side so it'd be closer.

driver side is closer to the battery, but there's so much stuff on that side of the engine bay that's in the way. the passenger-side grommet has much more room around it to work with. just cut off one of the two nipples on the grommet and u have your opening. no need to drill anything or push the grommet to one side. u can actually see through to the other side after u cut.

i had a hard time trying to get the 4ga through due to friction so what i did was take a hollowed out bic pen, shoved the open end into the end of the wire, wrapped some tape around both to keep them together better, and coated it in soapy water. and it goes right through.

bmac
03-02-2005, 06:44 PM
I ran my power wire (4ga) right thru the grommet you have picture, but I did need to cut the grommet and remove some electrical tape (which I redid after the wire was thru). It's not too difficult if you have two people working together. But, keep in mind that the grommet is two sided meaning that you will have to cut on both the battery side of it and the driver's seat side (at least I did).

With power lines, you want them to be as short as reasonably possible so I picked the driver's side as it is closer to the battery. I also found that there were plenty of 'other' wires and spots to ziptie the power wire too, so it looked good and fairly clean. Even with a fairly massive fuse. :)

GL,
B-

JLTD
03-02-2005, 07:32 PM
I ran 2 ga wire through the grommet that is behind the ECM. Drop the glove box and the ECM (3 bolts). and you can get to it easily.
http://img.photobucket.com/albums/v514/jltd/Dsc01661.jpg

brian
03-03-2005, 02:10 AM
Okay, just wanted to let you guys know how it went today. I ended up running it on the passenger side through the left nipple on the grommet that was already there. It was a huge PITA to get the rubber out so that I could feed the 4ga through it. That was the toughest part of the day since this car comes apart some easily. My back seats right now are kinda weird though, doesn't look like they line up correctly :(. Oh well, I'm going out to work again on it since I didn't finish hooking up all the wires to the amp/sub but they're all run at least. Thanks for all the help guys.

toyotaTOYOTA
04-21-2006, 02:53 PM
Whatever you do make sure you run the RCA cables and your Power wire separate... like with at least 6" of distance between them. Running them close will cause electrical noise in the RCA's --- translates to a humming sound in your amplified speakers when the engine is running.



actually that humming sound u hear when tha engine is running and gets louder when u rev tha motor is tha ground. make sure that u sand tha place before u bolt tha groud wire to tha chasis