grasshopper645

Wiring in an aftermarket stereo with a wiring harness but it wont get any power to it. Why is this?

Lee DeRaud

Do you have an adapter like this one or similar:
http://www.crutchfield.com/p_120SVI2...r.html?tp=3486
There are some signals the head unit needs to send to the car to make it turn on the main (switched) power line, something to do with the 'Retained Aux Power' circuitry, I think. Most head units can't handle it themselves and need the adapter.

grasshopper645

Lame... I used the exact same adapter in my 4th gen camaro which worked fine. What do I have to do to get power to the unit? Do I need to tap into another power for both acc and constant wires?

Lee DeRaud

Not sure I understood that: what I meant was, that's the adapter you need...and it works fine with no additional taps.

Paul 75 L82

Post this over on the audio forum. I didn't use an adaptor and got power from the data wire.

Lee DeRaud

You replaced the Bose subwoofers in the doors, right?

grasshopper645

Is there any way I can do it without said adapter

Lee DeRaud

I have no idea. The Crutchfield people said it was necessary and I have no reason not to believe it, since it works for me with it installed.

And if it worked in your other GM vehicle, why do you think it won't work in the Corvette?

grasshopper645

Sorry i miss understood you. With my camaro which has the same stereo but not the bose system. I was able to wire in a new stereo to the camaro without that harness. I am wondering if i can do this with the corvette without needing to get that adapter you linked.

Lee DeRaud

My understanding is, if you're only replacing the head unit, you need the adapter, at least for a "plug and play" solution. My install of a Kenwood head unit, using the adapter, never touched the car wiring: all the wire splices are between the adapter harness and the Kenwood harness.
If you're putting in an entire stereo (head unit, speakers, amps, etc), maybe not, but that involves more extensive mods to the car's harness since you'd be removing/bypassing the Bose signal processor and amps as well.


EDIT: and for some reason, the link I provided above to the adapter on the Crutchfield site has morphed to a link on Ebay for a different part at a higher price. WTF?!? Just go on the Crutchfield site and search for "Axxess XSVI-2004".

Sirk17

I ran power from my fuse box with an "add a fuse". The "Metro" or other wire harness doesn't get power, not sure why.

Lee DeRaud

"Metra" actually. Mine works fine, and I'm by no means alone. The two main causes when it doesn't are (A) defective unit (very small minority, judging by the reviews) or (B) failure to follow the instructions (everybody else).

According to the write-up on the Crutchfield site, it performs two functions:
1. It interfaces with the factory harness to provide both a milliamp-level always-on "keep-alive" 12V and a switched 10A main 12V supply to the aftermarket head unit. That part of the box also makes it play nice with the retained "aux power" feature: it stays on for 15 minutes on after you remove the key and shuts off when you open the door with the key out, just like the factory head unit.
2. It provides the level-shifting expected by the Bose signal processor so the subwoofers don't give a loud pop every time the head unit turns on or off. Part of that feature allows you to balance the levels between the amped subwoofers in the doors and the unamplified speakers.

Sirk17

I meant a normal 10 dollar harness not the fancy bose adapter one

grasshopper645

Yeah thats what i used which gets me no power

Lee DeRaud

One of the things I like about Crutchfield is that the "normal $10 harness" is usually free.

GCG

If you are only replacing the head-unit you will need an interface between the Bose system and your new stereo. The C5 Bose system is based on a modified Delco head-unit that uses pseudo-differential low level signals along with fully differential speaker level signals. The common signals are not standard and have a DC offset, so they cannot be grounded.

The way the system works the audio signals from the head-unit are "detoured" through the signal processor and then returned to the head-unit. At the same time, the signal processor adds up the information from the 4 channels and sends it to the 2 subwoofer amps in the doors.

The head-unit has 4 connectors in the back:
C1 / C2 (which is a single siamese connector) - power, ground, BCM data, front and rear speakers
C3 - power amp inputs
C4 - pre-amp outputs

The Metra adapter already mentioned, or the will take care of all necessary interfacing for you, making this just plug-and-play.