Fatfrii

i stumbled across these wires in the trunk of TL i recently picked up and am wondering what they are for. 1 looks like it goes to the back up sensors but the other is grounded to the car like it is for a amp and a subwoofer. loks like they are directly linked to the battery. can any 1 who has back up sensors shed some light and post up picks of their own?

d-townhakuzo

Some type of ground?

InFaMouSLink

iTrader: (10)

fuel pump bro

DeathMetal

iTrader: (2)

Black, ground, other, fuel pump; second pic, primary power cable

Fatfrii

can i hook up an amp to that ground?

Caiman

Yes, you can. I have my amp hooked to that ground. It works well.

CSWBiggs

I recommend that you don't actually...it's best not to share any ground paths with any of the vehicles circuitry...especially if you have a lower quality amplifier...you run the risk of pickin up the noise generated by the fuel pump...not to mention that it will be choking your ground causing you considerable voltage drop do to the increased resistance...can also cause alternator whine do to the voltage differntial...

my suggestion is find somewhere flat enough to use a large pan head screw to atach the ground cable to a properly prepared area....ie to the floor pan with the paint and anti corrosion coatings sanded away...please make sure no electrical,gas,or brake lines are behind where you r going to be driving the screw into...

Best of luck on your install...and if you have any further questions please feel free to contact me...

-Jason

P.S. - Shame on you caiman...an audio god that you claim to be is giving out terrible advice...tisk tisk tisk

BradE

TL doesn't come from the factory with backup sensors.

DeathMetal

iTrader: (2)

+1 against the ground point you are considering, absolutley terrible location.

You should consider any point between the amp and the chassis bearing in mind the shortest length will best suit your needs...and don't forget to sand, Sand, SAND before terminating the ground.

Fatfrii

yeah i didnt think it was a good idea but jason can u show me a pic of what u were talkin about cuz i have no idea about audio stuff im more of a gear head

Bender

+1 short wire and clean contact.

CSWBiggs

Hope these help...

-Jason

Caiman

Actually, I had a professional audio installer tell me that this ground worked fine. Thats why I use it.

I dont have any whine from the fuel pump, and i dont have any electrical problems.

If you think about it, the whole entire frame is negatively charged. So in that case, what would it matter if you used the same ground, or mounted it 2 feet away? They are both using the ground the same way.

CSWBiggs

than he is a very very lazy installer...he also probably uses the grounds that come on the installation harnesss'...

the goal is to isolate your equipment from every other item in the car...especially if they happen to generate voltage ripples

as you say that a ground is just a ground...try this experiment

do this with the car off...you're going to measure the voltage drop of both your positive and negative cables collectively..

take a DC mulimeter and measure your voltage at the battery...

now go to your amplifier's power connections and check the same dc voltage...

you'll notice a voltage drop...why...because the sheetmetal of the car (ground) has reisistance...when the resistance of a conductor goes up....the voltage drops the further it extends from the source....

so it might be a ground...YES...but a great one...far from it...

-Jason

Caiman

Alright cool... well guess im learning some real stuff here. lol not just what ive learned from installing myself

should I move the ground then? Its been fine so far...wouldnt want to cause problems later on ya know?

CSWBiggs

i'd recommend that you do...

-Jason

RBeachTL

Great pics Jason.

Got any of the primary power penetration into the cabin?

I've been looking at the guys here who have been going in through the unused hole in the center of the firewall but it's too small for the 1/0 firewall bushings and the hole is in such a PITA location that it looks like I'm going to have to take out the front sway bar and maybe some other stuff to be able to get a drill in there to enlarge the hole.

Sorry to hijack the thread but I'm sure you or someone else must have solved this problem.

jptl04

iTrader: (1)

no need to drill or remove anything. 1/0 gauge cable fits fine. i ran some for my install. others have as well.

RBeachTL

JP,

Yeah, I know that the cable will fit but what are you using to protect the wire as it penetrates the firewall? Are you using just a standard rubber grommet? I want to use the waterproof plastic bushings and they need a 1-1/8" hole; the hole is either 3/4 or 7/8".

Thanks for the help.

Trew

iTrader: (1)

My 0awg ground is connected to that point as well. I don't have any noise in my 2000 watt system.

Don't listen to Jason... He has no clue what he's talking about

My theory is DC electrons flow from negative to positive.

CSWBiggs

do i sense sarcasm?

:P

-Jason

DeathMetal

iTrader: (2)

You can run a 1/0 AWG through there just fine. While it seems quite the PITA, it's nothing in comparison to what most other cars require in order to go aftermarket.

Just some pointers:
-Take off the engine cover as it'll provide you a bit more room
-Use a flat-head with a thin profile to pry the underside of the grommet flange out
-You'll see some OE deadener/insulation - you can cut through it very easily once the grommet is remove (I don't know if you can route under it, I didn't)
-You're going to have to jump what seems to be a very small peice of metal inside the firewall, you'll feel it "hop" when you get over it
-Push a good 18" through, if you're lucky like I was, it'll be hanging right in front of your face

Seriously, use the existing grommet hole...while some things about the TL kinda piss me off, I am still floored at the extreme level of awesome that the presence of said hole has provided when compared with any other car I've worked on

If you're hardcore about protecting at the firewall you can try and cut in to the existing grommet and route through that location OR you can get what is known as a cable gland from McMaster Carr (or similar) to ensure a solid mechanical installation at the firewall

RBeachTL

Thanks DM,

I am trying to use an equivalent to the McMaster part:



Like I said this piece just needs a hole larger than the one that's already there.

What have you guys used? Am I the only one who thinks that some kind of protection is necessary?

AVongsana

bringing up an old thread, but I cant seem to find that empty grommet? the only one I can find is where the main wiring harness goes, and its pretty tight for me to even fit a 4awg? am I missing something?

i'm working with an 08 tl-s, and there seems to be more in the way than in deathtotoasters picture.

InFaMouSLink

iTrader: (10)

you can fit a 0 through there.tape up like a 16awg to it, run that first then pull the 0awg through.

AVongsana

wow, great idea. it worked!

thanks infamous

bzyrice

iTrader: (10)

I used the original gromet that was there.. Just cut a big X in the middle of it and pushed my wire through it..

A SiQ TL

Damn, I literally just finished putting an amp and subs in and I used the same ground. Looks like I'm gonna have to go back and make a new one.
Thanks Jason (no sarcasm honest)