Bose power trigger????

[ledrocnoc]

I _did_ run a few searches and couldn't find any answers on the forum... so here my problem:

I just bought a used Kenwood KCD-X979. The unit has an internal amp but also have a pre-amp output.

I got the Metra VW harness, connected it up (for some reason I had to swap the battery and power wires... works now), and plugged the pre-amp out from the head unit into the Metra harness.

Head unit powers up... but no sound coming out of the speakers.

The make sure that it wasn’t a problem with the HU, I plugged the pre-amp out into my home stereo Aux input and it works… So as far as I can tell, the problem is not with the HU.

I plugged the stock HU back into the harness and everything still works great.

So… it’s either the HU not putting out the right output (low probability, I would expect to get something, even if crappy) or there is a mismatch in the wiring.

I did some search and found a page with the pin-out for the Mercedes connectors (not my car / year, but it looks pretty damn close): http://www.whnet.com/4x4/MY2000_MCS_pins.html

Looking at Pin A05 it says “Bose premium sound system power trigger”… and I am wondering it the Bose amp needs a power-on signal (something the tell it to either turn on, or amplify…)

My HU has two wires:

- One labeled “P. Control”. The manual (I have to say, the Kenwood manual is one of the worst ever) says: When using the optional power amplifier, connet to its power control terminal

- One labeled “Ext. Control”, which according the manual goes to “terminal on the amplifier hading the external amp control function”

My Metra harness had a couple of spare wires in the bag, one blue and one blue/white. On the Metra bag, where they list the color coding, the blue/white is labeled Amp –turn on…

Any clues on what I should be doing?

Thanks

[NISMOPOWERED]

I had to bypass my Bose amp to get mine to work but then the speedo didnt work with out the factory radio. I still have not looked at it any more.

[ledrocnoc]

OK, I spend some time with my voltmeter and figured out that the Amp Control pin do need to be connected. Works great now.

I have also connected my Power Keg (Kenwood Hard Drive unit) and it works fine. Just need to upgrade the cartridge from the puny 10GB to something more usable :-)