Car Stereos: Install of aftermarket radion in 2001 gmc yukon, gm bose, pioneer deh p47dh

Question
I bought a powered Pioneer (deh-p47dh) aftermarket radio with a wiring harness.  I wired up the adapter harness to the radio and plugged it.  I get power, but no sound.  When I plug my stock stereo everything works just fine.

My 2001 GMC Yukon is stock equipped with Bose and Onstar.  Would this have any affect on this problem?

I also took the Pioneer radio to the shop and it bench test just fine.

Thanks in advance.

Answer
Hi Paul,

Sorry for the delay in answering your question.

It's likely that your problem is caused by the Bose system, in two different ways:

First of all, the Bose amplifier needs to be activated when the after-market head unit is turned on.  This is done by connecting a activation wire (often called a "remote" wire) in the factory radio plug.  Usually this is a dark green or orange wire in the main radio plug, but in Onstar-equipped vehicles, the remote wire may be pink or orange in the smaller, secondary plug.  In either case, the wire must be connected to the blue/white remote output from your new head unit, in order for the Bose amplifier to turn on.

However, there's a bit more to the system as well.  The Bose audio system uses four separate (+) signal wires from the head unit to the amplifier, with two common (-) wires--one for the front audio, and one for the rear.  This type of wiring isn't compatible with an after-market head unit's speaker outputs, and it doesn't work well with the low-level RCA outputs either.  That means, if you want to use the Bose amplifier with the new head unit, you'll need a special premium sound adapter module to go between the new head unit's outputs and the factory radio plug.  An example of this adapter is PAC's OEM-2 (also available as Peripheral Electronics' SVEN4).  Be sure to check the adapter's installation manual for the specific wiring required for use with a GM Bose system; you have to do things a bit differently with these vehicles.  Here's a link to the PAC adapter's manual, to give you an idea:

http://www.pac-audio.com/PACProductData/OEM-2/1_Instructions/oem-2_instructions_...

Hope this helps!

Brian