GMT900 Bose Premium Amp to Luxury Amp Upgrade

[Reebok59]

Bill,
You are correct that it should have worked (front speakers only) if the head unit indeed needs no reprograming. From what I understand, the prem and lux amps work totally different with different input levels from the head unit. I would think your head unit needs to know which amp it is hooked up to. If that is not your problem, your amp may be bad. I fried my first amp by hooking it up to my non-reprogramed head unit and powering it up!
Good luck

 

[roadcrew]

Hey Scott,
I may have just realized something. I recall that you said your vehicle has RSA and therefore GMLS will already be present on A6. My truck however, does not have RSA. I noticed in one of the links you referenced where "licensetokill" picked up GMLS from behind his radio and put a jumper down to A6. I wonder if that could explain why my lux amp is not playing? Could that be needed to trigger it?
Bill

 

[Reebok59]

Yes, definitely need GMLS connection. That is what turns the amp on and controls the volume and every thing else.

 

[roadcrew]

Hey Scott,

Success! Yi-peeeeee! My second lux amp arrived. . .turns out the first amp, like yours, was bad. Now I just have to get the rear speakers to join the party, and I'm done! I'm thinking since I got a Y91 harnesses with each amp, I might harvest the pins/wires from one J108 to add to the other and connect the rear speakers that way (rather than cutting in behind the kick panel). I recall you mentioned pulling pins from these connectors. . . I've done it before with older GM plugs where you just bend the metal wings over by shoving in a paper clip. But for the life of me, I can't figure out how to get the pins out of these. It looks like you have to pull a little flat plastic tab forward for each pin. . . I can get the pins halfway out, but from there I can't see what's holding them in. I can't pull them out, nor can I push them out the bottom. I'd prefer NOT to break the J108 plug to get the pins out. Can you describe how they come out? Do you cut the wire and push them out the bottom, or pull? Is there some other trick beside the little plastic tabs that release them?

Thanks man!
Bill

 

[Reebok59]

Yes, there is a plastic retainer inside the connector. If you look close at the connector itself, it will come apart in two or three pieces. You can completely or partially take it apart and the pins will come out. I found this method eaiser than the paper clip method.

 

[tights24]

I hope you don't mind if I piggyback into this thread and ask a question as it seems you did quite a bit of work on this and have had awesome results. So first, thanks for the write up, pics, and details. Now, my question is this. I see you referring to regular and luxury amps and I saw the picture of the two side by side. I have a yukon SLT with the bose system and rear entertainment but no nav. I have pillar speakers as well as a center channel. Does that mean that my amp would currently be the luxury amp to start with? the reason i am asking is because I think a channel is fried as I have no significant sound coming out of my left front and rear door speakers. I heard a loud pop a few months back, and ever since it hasn't sounded quite right. lol. My guess is i fried a portion of the amp. All I am trying to avoid right now is ordering the wrong replacement amp and getting my console torn apart only to find that I have the wrong one. lol. Thanks.

 

[Reebok59]

I would be willing to bet you have the Lux amp since you have the center channel. You can call your local GMC parts counter and give them the last 8 digits of your VIN and they can tell you the part number of your amp and if it is a Y91 Lux amp or not. Also inside your glove box there should be a Y91 RPO Code if you have the Luxury Package. Either way, you need to know your P/N before you order a replacement amp to make sure you get on that is compatable with your system. Call GM parts or remove your console. Good luck.

 

[tights24]

Thx reebok, completely forgot about the codes in the glove box. smh. lol

 

[tights24]

Just an update after reading through this thread again as well as the Sierra thread. I have no idea why I thought I had a center channel, but I don't. I have all of the same RPO codes as you except the Nav code. My glovebox shows UQA, U2K, U42, UK6. I assume this means I have the premium amp and not the lux amp. I'm thinking now that my best bet is to open up the center console and take a look at my amp and just try to find one with the same part number that works. lol. regardless, thanks for the help and all of the info you posted. I probably will not go down the path of actually adding speakers. I just wish I could use the lux amp to simply add better sound to the existing 6 speakers and make sure that my rear DVD works and speakers controls were all the same. Oh well.

 

[roadcrew]

Hey Scott,
After that advice you gave me about the J108 connector, I took another look and yes, it was very easy to disassemble once I removed that blue "comb" that retains all the wires at the back.

Everything is working beautifully now, got the rear door speakers connected, but I noticed something curious. I can't fade between front and rear. When I move the fader control full rear I get silence. But when I move the fader to neutral (midpoint) the front/rear door speakers have equal volume. It's as if the four door speakers are on the front channel, but they're definitely not. I can live with it (like your muting issue) but like you, I'd like to have full functionality if possible.

My lux amp came out of a late model Yukon. I don't know how SUVs are set up. . . could it be that maybe fading occurs between the four door speakers and the d-pillars? Does yours fade that way? I don't have d-pillars because I'm in an extended-cab truck, so I'd have to hook up a couple spare speakers to try it. I've triple-checked the wiring and my rear speakers are definitely on the rear outputs. The only other possibility is an issue with my head unit. Any thoughts?
Thanks.
Bill