I've installed a mono amp to power a sub and a 4 channel amp to replace the factory amp to power the car's speakers. The problem is I can't seem to find a 12v source for the on/off relay wire that will keep the amps powered after I turn off the car but before I open the doors. I've been able to hook them into an accessory power source but that cuts out unless the car is in accessory mode or turned on. The deck stays on until you open the doors so I was wondering if anyone with knowledge of the electrical system could advise me of a location to put that relay wire so I can keep that feature. Thanks.

 

Why not take it from the power source on the head unit? It obviously powers the head unit till you open the door. In a base model car it is on the 8-pin connector and is red with a black stripe.

 

I have done many head unit swap outs from factory to aftermarket and they have made a significant improvement to the factory speakers.

Let me know how this worked for you as I am looking to upgrade the sound system as well.

Not sure what wire to use but get a volt meter and look for red or yellow wires.

 

I'm not sure which wire you're referring to, but there isn't a factory switched power source at the head unit that I have ever found (and I spent a lot of time with my meter!). The power on/power off signals come over the serial data bus, and that is how RAP (Retained Accessory Power) is achieved. The only way I know of to get this is to use a module like Peripheral's GMRAP that you tie into the data bus and it outputs switched 12V.

http://peripheralelectronics.com/pro...?ProductID=170

 

I honestly can't remember if it is at the head unit or at the amp but clearly there is a power wire provided to either the head unit or the amp otherwise the factory head unit would not have power. Thinking back, it may very well be at the amp. Here is a pic of that connector. The red with black stripe is the power.

 

hmm...reading your post again, you might be right. It's been about 3 years since I was in depth with these and it may very well be just a trigger signal sent to the head unit and amp.

 

Only because absolutes have a tendency to swing back around on you, I'll say I'm 99% certain this is the case. I certainly haven't seen a 12V RAP "trigger" in any of the harnesses.

 

Has anyone installed a peripheral GMRAP? Is it compatible with a 2005 Corvette? Are there different types or models? Thanks for all of the help so far!

 

There is only one GMRAP and it is compatible and if you click the applications list in the link I posted you will see the 2005 is on the list. And since nothing has changed in the serial data bus or stereos of the C6 that is true all the way through 2008. I don't know about 2009 yet.

Out of curiosity, what did you use as the signal source for your sub amp? If you tapped the rear speakers, you're not getting what you think you're getting.

 

I ran two sets of RCAs from the head unit to the 4-channel amp and then another set of RCAs out from the 4-channel to the mono amp.

 

Sorry, I was focused on the sub part, first time I've seen someone run a different amp on the stock speakers. Be VERY careful with the volume **** on that. The stock amp is something like 18W and I expect that whatever amp you installed is likely capable of launching the voice coils in those factory drivers straight across the car.

 

Let us know how it all turns out.

 

Alright, well I've ordered a GMRAP so I will let you know how that install goes.
The system sounds great now that it's almost done. I've replaced the front and rear speakers with Phoenix Gold Rsd 6.5 and Rsd 5.25 component speakers. I had to drill 1 inch holes in the rear panels beside the existing rear speakers for the tweeters that came with the set. They came with crossovers too, to filter out any real lows, so without a sub I would have no bass at all. I just unhooked the center speaker in the dash all together. I also built a box to house my 10" Alpine R-type sub which I'm running off of an Alpine MRP-M650 amplifier. Then I rewired all of the speakers and I am running them off an Alpine MRP-F450 amplifier. One of the hardest parts of the whole thing was running 0 gauge wire from the battery to the trunk. The speakers all sound really clear with virtually no distortion, even when I have it cranked. And now I don't get any rattling from the doors like I used to from those factory subwoofer-type things that were in the doors before. I would definitely recommend it to any audiophiles out there. Thanks for all the help.