1) We know for sure that it is either 4V or 5V (Not helpful but it's what I've got)
2) As far as I know (I have 4V preouts on my HU) 5V preouts work just fine and the volume control is not too agressive. Several people on here use 5V.*
3) There are no gain controls on the amps.
4) There are two amps. A four channel mounted under the rear deck in the trunk and a single channel attached to the subwoofer itself (also under the rear deck in the trunk).

*Those that have used 2/2.5V preouts and reported back to this forum have ALL been unsatisfied with the output.

Thanks for the clarification. I think I will likely get that JVC deck with the 5v output. Unless I decide I need touchscreen or something.

I also did some rough calculations and I figure even if the bose system is 4v, if I have a 5v deck I would be close to the correct volume. According to my calculations I would be off by about 25%. So with the volume **** at 50% I would actually be hearing 62.5% volume (50% x 1.25) At 75% The amps would be at 93.75% and I would hit full volume with the volume **** at 80%. It doesn't seem like that should be too bad. Of course that assume the bose deck is 4v. It could be 4.5 or 5 or even 3.5v for all that anyone really seems to know. I guess we really don't know. But if others are using 5v without issues then I should be good. I guess thats all I really needed to know. Thanks for all the help.

I just placed my order. Does everything look right here:
Thanks for all the help. Sorry if I hijacked someone elses thread.

Yup, don't forget the ASWC if you want steering wheel controls.

Thanks. I decided against that. The only time I use it is when I hit it by accident and it messes up my radio. I decided I'm better off without it. Its not like its a long reach to the radio or anything. Afterall I'm sitting right there.

Thanks for all the help. I'll try to post back my results when I'm done.

I have a pioneer in dash TV in my max with factory Bose speakers and amp. You do not need a harness just connect the amp power wire from your radio harness to your remote turn on wire and your done.

Just thought I'd let everyone know that my install went great this past weekend. I used the following items:

1. JVC KW-R900BT:
2. Metra 95-7416G:
3. Metra 70-7551:
4. Metra 40-NI10:

I don't think the install could have went better (apart from my bluetooth phone not working properly). The JVC with 5v rca outputs worked quite well. I don't think volume changed much if any. I may have lost just a tad of volume. So I would say that the stock deck is very likely a 5v output, maybe even a 5.5 or 6v output if it was done to custom specs.

The only issue I have is that I lost the trip computer. I didn't get the steering wheel control module because I didn't want steering wheel controls. But I was kind of bummed that I also lost my trip computer (Avg mpg, distance to empty, etc). Has anyone else noticed they lost the trip computer if they didn't use the steering wheel control module? Any easy fixes or do I need the module?

Easy Fix. Connect pin 11 of the 16 pin vehicle harness to Ground.

Thanks, I wondered if it was a simple ground issue. I should have asked before I reassembled the whole dash.

getting all my wiring together for my pioneer z110bt, ive read about the preouts, metra kits, etc, and this is what the z110bt is listed for:

High-Volt Preouts x3 (4 Volt) for clean, powerful signal to optional amplifiers

Will this head unit work with the factory bose amp in an 03 maxima using the metra kit or any other method? looks like the metra kit has 4 rca connections, if the headunit just has x3 4v preouts i assume this headunit wont work or am i misunderstanding?

thanks in advance