Ok, this is nagging the $#17 out of me.

Metra 7552 does not have an amp ground connection like 7550 did. I looked up the wiring diagram on the 07 Max OEM harness at Metra. There's an amp ground wire...

Would not having this wire grounded on the head unit side (I guess the other side is just connected to the amp?) cause the hissing I'm experiencing?

Would this even make a difference? I ask that, because when I cancelled the amp on the head unit, I got zero output to the speakers. I'm guessing that the only thing 'amped' in the car are the subs. On second thought, that's a stupid question. It seems that could be injecting quite a bit of noise into the mix.

Why the Hell didn't they put an amp ground wire on the 7552?

Guess I have to rip the dash off, one more time. Sigh.

 

wait, so how is the head unit grounded?

good thing the dash is pretty east to take off in our cars.

 

The HU is grounded to the metal bracket around where it's mounted. Galvanized metal. I guess the Bose was just grounded through it's cage?

I've run into a brick wall. I can't tell if there's an amp ground wire on the factory harness. None of the colors match up to the Metra OEM harness descriptions. This seems like the only plausible explanation as the factory head unit had zero hissing... I just can't figure out where the amp ground wire is, if there even is one.

You pulled out a factory amp before, right? Was it grounded at that amp or at the head unit?

 

Okay, I won't be coy. Is there anyone that knows what wire is the amp ground wire, on the factory harness, for the 2007 Maxima with Bose?

The OEM replacement, from Metra, lists a black/yellow wire. This is not present, on the original factory harness. There are, also, four black/grey wires on the original factory harness leading me to believe that it's not black.

I have Googled, `till my eyes are bleeding. I cannot find an 07 Max stereo wiring diagram, to save my life. I, also, Googled newsgroups. Still, no dice.

 

you can try tracing the ground with a multimeter.

i didn't pull my amps out, then again i didn't have the bose package.

 

I re-ran the speakers through the pre-amp outs. That got rid of the hiss. At the same time, reducing the volume to less-than-stellar heights. Seems that by going through the line-level outs, the signal was becoming over-amplified. So, now I just get the joys of low engine whine and low volumes. Better than that @#%@$%$% loud *** hiss.

Can't wait to replace the speakers and amps and be through with this Bose crap.

Stront

 

Having the pre-outs send the signal is causing lower output because of the low voltage. You need a unit that has higher pre-out voltage in ordr for the volume to up itself or a line driver.

 

5.6V is 'low'?

 

Must be just a lil too low for the bose, what model headunit?

 

Clarion DXZ675USB

 

Are line drivers expensive and/or a pain to install? Would there be any risk to the head unit, by using one?

 

As much as I didn't wanna open that dash and solder/heat shrink wires again...

I picked up 2 NIS-35's for $30 and reverted my wiring back to the line-level outputs. I, now, have loud music with hiss at only the top end - where it belongs. And, engine whine is gone.

Edit: Oh, and the CEL didn't come on this time, when I reset the SRS light lol.