Hey all, buddy of mine picked up a '04 G35 Coupe, automatic a few months ago.
Just recently we've been dealing with the classic power drain issue.

We've gone through two dead batteries until we've decided it's not a battery/alternator issue (that we know of, now.)

I've done a bit of reading, and it looks like it's the typical Bose HU (or amp?) that has the resistors (?) that are letting the power drain.

However, we have a Kenwood after market HU w/ Nav & Sirius, which makes me consider to perhaps be an issue elsewhere.

I haven't found much besides the above, and all of the threads I've been reading are from '08-'10.

Is there a new updated way to prevent/stop this parasitic power drain?
We've pulled the fuse for the time being; and we don't want to put a relay as we'll lose all memory everytime the car is restarted.

 

Bose amp is a common cause of parasitic drain, and it's an extra good reason to replace it.

 

So it is not the Bose headunit, but the Bose amp?
From the posts I've read it always appeared to be the Bose headunit.

Do most people replace the Bose amps with normal 4 channel amps, and place them under the front seats?

I've always read it was a simple diode that blows, I have experience working with many circuits, but if it's not confirmed; I'd rather not play with it.

 

Not sure about the coupe but I know on my sedan there is no room under the seats for anything bigger than a bday card much less an amp. The electronics for the power seats pretty much take up all the space. Almost all members here mount amps in the trunk. And yes, get rid of every POS Bose part in the car, it's crap. I've had 3 cars with Bose audio stock and the other 2 had really good sound and quality components. The G not so much though. I've got an 05 sedan and am running a JL 300/4 bridged to 2 channels to run my front components and a JL 500/1 running a 12" sub in the trunk. They are mounted to the back of the back seats in the trunk, super clean and out of the way.

A lot of us recommend the "front soundstage" theory with the thought that less is more with speakers. My system has gotten tons of compliments over the years and I've been thrilled with it.

Show more





Show more

 

The Bose headunit fails for lots of other reasons (so does the non-bose headunit), but power drain isn't common from the headunit.

Pretty much everything Blue Dream just said is spot on too.

There's a surprisingly large amount of room in the trunk where the coupe amp sits. I've put large amps there twice now. Most amps can even be oriented to connect to the stock speaker wiring without extending it. All you need to do is run power and ground wires.

If you're keeping your stock headunit you will need to go with an amp that takes differential balanced signals - JL amps all do, but I don't have a list of other models by other brands that do.

 

Thanks Blue Dream & Wrathernaut.

Currently the G has a Kenwood DNX5120, with unknown amp (haven't had the time to peek in the trunk, yet).
It looks like the PO had the JDM DD kit installed, the portion where the nav would usually pull up, is actually a storage cubby space.

I'm thinking the PO had new HU put in, and potentially new speakers (not sure, I'll have to check when I go in for the door actuators).

Since we have a Kenwood DNX5120, any normal 4 channel amp should fly, right?
Stock wiring harness should be okay?
We're not looking for anything crazy, just something that will run the audio. Not an audiophile by any means.

Unricing a ricer's G35 is painful, sometimes..
It looks like they put a gauge of some sort (that doesn't work!) in where the clock would be, and mangled the steel bracket for the clock.. I'll have to figure that out at the same time...

 

Yeah, any amp well do.

 

Had a chance to take a look under the trunk liner, it's definitely a stock Bose amp.

I believe our options are:

1. Replace w/ replacement Bose amplifier, potentially have sane issues in a few days/weeks/months.

2. Repair Bose amplifier, lose out on SQ (not a huge deal).

3. Replace Bose amp with any old after-market amplifier, T-Tap into stock wiring harness, run power wire straight to the battery, and chassis ground.

Can we replace any old 4 channel amp for the Base amp, without changing any wiring/connectors?

 

The Bose amp is 6 channel, so a fou will only run the front door and rear deck, but that's fine.

If you replace the amp, don't mess around with the t-taps, orient the amp right and just plug the wires in. If that's not possible, solder and extend them.

 

In that case I'll pick up a 6 channel amp, roughly what amperage rating should I be looking at?
I know typically Bose uses some abnormal impedances which can complicate things.

I was also unaware that I would be able to plug and play, I read up elsewhere that the way the Bose amp takes in connections is different than typical.

I was under the impression that most people rip out all of the Bose electronics and re-run their own wiring because of Bose's... "Interesting" connections.

I didn't have the time to rip it out to see if it has RCAs quite yet.

 

There's not a lot of 6-channel amps to choose from, any of them are going to be more powerful than the bose system - just keep the gains down and you're fine to use it with the bose components until you replace them. Pick the power based on what you need for your projected replacements.

The bose components are 4 ohm. The wires are the same for the bose system, it's the signal sent over those wires that complicates things, so without the bose headunit or amp, you don't need to worry about it at all. It's just two wires, like pretty much everything else. No special wiring or connections.