i am replacing the bose (cdr23 and the amp) with a single Din Pioneer Deh-80Prs and a Five channel Polk amp.
I measured the current at the factory harness constant power and it works. Same with he phone connector in the middle console, switched and unswitched leads carry current.
Here is the mistery. HU will only turn on when key in acc position or the car is running. When car is off, unit will not turn on but receives >12Vand does not lose memory. Is this a system issue, anybody with similar problem. I connected the HU directly to tne battery using conctant power lead (yellow, +) and black(-). HU will not turn on, only when i swap yellowfor red(switched power) lead.
Also i cant find the brown alarm cable (read all posts about where to find it) but the radio removal alarm comes on when aftermarket unit installed.
Thanks for your help and suggestions.
BtW, there is only one sweet spot for this amp, almost too big, but can drive the bose subwoofer in my 2004 996 converible.

 

Yellow = battery, constant 12 volt and supplys memory back up.
Red = switched power. 12 volts is only there when key is in ACC or ignition on position
If you want to operate the radio without the key in, you would have to have both red & yellow together on the car yellow (constant 12v)
Just don't forget to shut off the radio.
I'm not familiar with the brown alarm cable.
Can a durametric defeat this maybe?

 

On my car the brown wire was terminated with a spade lug connector. The spade was attached to a small metal tab about halfway back on the left hand side of the radio opening. My understanding is that this tab normally rests against an insulated area of the radio. When the radio is removed, the tab comes into contact with bare metal. This triggers the radio removal alarm.

Aftermarket radios do not typically have the insulated area for the metal tab to contact. When I installed my aftermarket radio, I disconnected the spade from the metal tab, insulated it, and carefully taped it off. I suppose another option might be to use tape or an adhesive rubber pad to create an insulated area on the side of the aftermarket radio. This would have the advantage of allowing the radio removal alarm wire to remain in place and serve its intended purpose. I couldn't do this because the mounting cage for my double DIN head unit is in the way, though I guess I could've cut an opening in the mounting cage for the alarm tab.

From your description, I'd suspect one of two things: either the brown wire is in place and the metal tab is in contact with the chassis of the aftermarket radio; or the brown wire has already been disconnected from the metal tab, but was not insulated and is coming into contact with bare metal someplace else behind the dash. Given that you can't find the wire, the latter seems plausible.

 

The orange on the factory harness or on the aftermarket harness? Because if you're talking about the aftermarket, unhook that and see what happens. The illumination wire is the only thing I can think of that would link the two pieces of equipment.