Hey not if anyone has figure it out yet.. but my best guess its something to do with the stereo and out circuit board there are multiple postings on this in other forums.. other forums is Edmunds.com Infiniti G35 Electrical Issues...I have yet to be convinced its either the radio or that circuit bd(between the cd/radio
heres one from someone
Ok back on track...
I found this post on another forum that seemed interesting......
"I've just solved my 2003 G35 Bose Radio/battery drain problems. Replaced the radio with a Pioneer FH-P4200MP radio. Used a Metra Dash kit, Metra antenna adapter, and a Metra Amplifier wiring harness. The steering wheel controls were adapted with a PAC SWIX interface unit.
Took the installer about 3 hours to do the replacement and the sound system for the first time actually sounds like something one would expect from Bose. The Bose speakers with this set up are phenomenal.
The Bose Amp was left in circuit.
Here is what is happening. There is a signal from the factory radio that goes to the Bose amp that tells the amp to turn on, or turn off. This signal mechanism gets stuck in the On position. So your amp is constantly on , even if the radio is off!
If your Bose radio is still in the car, disconnecting the amp in your trunk will stop the battery drain, and keep the HVAC controls intact. The radio will still turn on, but no sound will be heard. All you have to do is locate the amp and remove the wiring plug.
Battery Problems:
The constant drain on the battery causes damage , and after a period of time, even if the amp is disconnected, the battery will not hold a charge. Battery replacement is the only solution.
Things got so bad for me that the low battery voltage caused my main computer to need reprogramming - at a cost of 180 dollars.
The radio, the install kit and the installation cost me about 700 dollars.Toss in the 180 dollars for the reprogramming and the cost of a couple of batteries and this whole mess cost me 1000 dollars.
BTW...the Bose radio in 2003 G35's comes from Clarion. "
So I went out and disconnected the amp in the trunk and did the amp drain test again. No luck, the draw problem was still occurring so in my case I assume the amp staying on is not the problem. Back to the circuit bd I guess. :7(
The plan is to pull the bd in the very near future and get it over to my pal who will run some diagnostics on it to see if we can pin point the issue. Stay tuned.
I took the radio assembly out last week.
I forgot to take the CD's out of the deck so took the unit back to the car and plugged the three connectors back into the back of the unit to see if I could get the CD's out.
... As soon as I inserted the last connector the radio/CD unit comes alive and out pops a CD????
There is no key in the ignition and the car is off! Interesting to say the least and the first clue to locating the bug.
As you know I could not figure out how to separate the top and bottom units which would allow access to the board in question.
I then handed the unit over to my pal would wanted to have a stab at it.
He called a couple days later. He figured out how to get at the board and was doing a full PD on the board. He discovered something interesting. He had me take some voltage measurements at the car here (he is in another city an hour away).
Well what do you know..... Looks like he may have found the bug, the cause of the parasite drain.
Will update again once we verify.
Just a quick update folks.
The bug appears to be a manufacturing error on the board. My pal made a change to the board. I got the unit back from my pal and installed it last week.
I did some amp checks and confirmed the battery drain problem is gone
The reading between the -post and ground was about .55 (with the battery drain issue), and is now sitting at .07 With the radio fuse out it was/is .05 so a huge improvement.
The only issue I have now is I have lost one feature. If the radio is on when I turn the car off, it is off when I turn the car back on. I then have to physically hit the radio on button to turn the radio back on. May be a memory support voltage or line issue.
Will do some further checks to see if this issue can be corrected. I may have put this bug on the vehicle when taking it apart and reassembling.
Will let you know what I find out. Need to wait for a warmer day as the car is outside and this is Canada...lol