Is the red wire "always" hot?

[greenmtnman]

Hey guys
first post

I recently purchased a 99 Z Coupe 2.8L (august)

I just replaced the aging receiver w/ a nice Sony unit because the factory CD player in the hatch doesn't work.

Problem: the damn thing won't stay out of demo mode. I did what the book said to get it out of demo mode, and then when that didn't work I went online and followed a video tutorial of my exact receiver.

Here's what happens: I get it out of demo mode. It is fine while I'm driving. If I turn off the car for less than maybe 1 or 2 minutes, the receive will retain my settings. If it I turn it off for say, 5 minutes or more, it goes BACK into DEMO MODE.

My question is, it seems that perhaps the car is cutting power to the amp after a certain amount of time, so then the receiver is resetting after some period of time. Is the power always hot? Or does it turn off or something?

I ask here because it seems if this is true, others would have experienced it and may know a solution.

The alternative is the amp is defective, in which case I have to disassemble, but luckily I got it from crutchfield and they are stellar customer service wise.

[Mless5]

You need to have a constant 12V and switched power. On Sony's harness, yellow is usually always hot and red is switched.

[greenmtnman]

You need to have a constant 12V and switched power. On Sony's harness, yellow is usually always hot and red is switched.

Interesting. All wires matched up with the supplied harness, but maybe I need to do a little custom work to make sure I use the always hot. Thoughts?

[Iveexcaped3]

Almost all manufacturers use yellow as their constant and red for switched. Pull up the Sony manual and it will tell you what wire needs to do what.

[Mless5]

Almost all manufacturers use yellow as their constant and red for switched. Pull up the Sony manual and it will tell you what wire needs to do what.

There is also usually a sticker right on top of the radio with the color coding.

[Iveexcaped3]

usually but if the OP got it 2nd hand or is an older one it can rub off. almost all new decks have stickers straight on the wires telling you what it is. Just giving the OP another option if labels aren't available to them.

[greenmtnman]

Yes, mine didn't have any sticker on it, I guess because it was open box (this is my 4th install on various cars never had this happen). I pulled it out last night and looked- nothing. I looked in the manual again (I did on install) which was only marginally helpful. As I have all wires soldered and shrink wrapped in what appears the proper positions- there are no wires left or unused on either harness- I think I need to bypass the supplied BMW harness and put the "always hot" wire directly to the yellow one of which you guys are speaking. I didn't get past that point last night but hope to tonight.

[Iveexcaped3]

Me personally I don't solder my radios, it's a waste of time imo. You want to make sure that the yellow is all time hot before adding power to it. You don't want to chance messing something up.

[greenmtnman]

Me personally I don't solder my radios, it's a waste of time imo. You want to make sure that the yellow is all time hot before adding power to it. You don't want to chance messing something up.

I usually just shrink wrap, but this time I soldered because my coupe is a boyhood dream car and I just...I want to treat it right...so I find myself going over the top ha

I'll break out the multimeter to make sure!

Thanks for the replys everyone, I'll update if it works so anyone searching in the future will know.

[greenmtnman]

AH HA! Turns out it was a firm ware problem. Downloaded the files to a USB, and problem solved.
Thanks for the help guys.

[greenmtnman]

Oops: not fixed
Turns out the amp was faulty. I checked the wiring, and despite a constant voltage of 11.2-11.5 V incoming all the time, it still kept resetting.
Sent back, now have another one on the way, we'll see if this fixes the problem. Trying Kenwood now.