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Discussion Starter · #1 ·
Need some help. :confused: I spent all day running and locating wiring for 2 amps in my 08 trailblazer and I got to the point where I had power, grd, rem, RCA to the first amp that I want to run a 2 channel amp to power my front 2 components ( the red LED light is on). I ran the speaker wire straight to the inputs on my front components but I get no sound. Am I missing a step here? The 2 amps I have are older but last known in working condition. The stereo I'm using is a kenwood DNX7120 all in one system. It works just fine but I want more power to the components and the sub I'm installing.
I'm not sure if I have an amp issue or RCA/ wires!?:bonk:

Any suggestions would be a huge help.

Thanks in andance.
 

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Where do you have it grounded?

How do you have the power distributed between the two amps? are you using a dist. block for power and ground, power only and individual grounds, or something along those lines?
 

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Discussion Starter · #5 ·
I used a second nut attached to a bolt that holds in a module (black box) under the passenger seat. For the power I ran a single 4 gauge wire from the battery to a dist. box that steps down to 2 individual 8 gauge wires 1 to each amp ( I was only working on the first amp setup for now). Each amp will have it's own grounding wire.

It I actually did have a bad ground, would the power light come on when the head unit starts up?
 

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yeah that's a bad ground. It would cause your protect light to come on and get no sound.

Not that I am recommending it, but the seat belt bolt is a better grounding location then the fuse box under the back seat (btw thats what that is :) )

I personally grounded mine directly to the frame under the vehicle, but that might be a little further then you want to go. I would make a ground point, possible to do it under the rear driver step panel (common for local audio shops to do it there) just use a self tapper and o-ring still not THE BEST, but you could also try the seat belt bolt, I know a lot of guys use that as well
 

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Discussion Starter · #7 ·
okay I'll try that. I have the amp under the front passenger seat. Maybe I'll try the seat bolt. so what your saying is that I can't self tap a grounding screw to the body, it needs to be the frame?

Also how would suggest I connect the new speaker wiresz from the amp to the speakers?
 

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You can self tap to the body, gonna be the easiest way to do it.

There are several ways to go about the wire, you can either run new speaker wire to all the doors (PITA going through the molex plugs) which is the best way to do it, or if you have the standard system in there (no bose) you can run spkr wire from the amp to the back of the radio and tap into the factory wire. If you have bose, same concept, but instead of running all to behind the radio, you have to run them all to the factory amp in the cargo area behind the passengar side panel.

I would recommend the full re-wire, going to the back of the radio is kind of a [email protected]$$ way I think, some installers (at my shop as well) will do it from behind the radio to save time, it also saves the customer some money, but in your situation, go from each speaker to the amp with new wire.
 

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Discussion Starter · #9 ·
okay thanks, Maybe if I don't run the wires to the speaker directly I could tap into the speaker wire right before the wire goes out to the door.

Another question, I have a Kenwood deck. The other thing I'm not sure of is that I might have to turn on some sort of pre out setting. I know there is a button to turn OFF the sub pre out but I can't see anything for the other 2 pre outs. Any thought?


Thanks for all your advise. :)
 

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Connecting right befire they go into the door works, but I would also cut them so they dont run through the vehicle, you could run into some noise if you dont.

I actually currently have the DDX-814 (just got it last week, 94th one made:cool:, actually got it before my company did:D)

the sub is the only pre out that you turn on and off. for the 4 channel as long as everything is connected properly, you should be good to go

the 7120 is really nice still, I wanted the built in nav, but I didn't have enough points to get it, I can always get the kna-g510 nav upgrade if needed
 

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Discussion Starter · #11 ·
Ya it was a bit pricey around $860 but the nav system is pretty cool. I must say I was pretty disapointed after so many hours of running wire and making it all so clean to find out I had no sound from the amp. I'm building a custom enclosure that will fit into the rear quarter panel where the boss amp would be. It will house a 10" type R alpine.
 

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should sound good once everything is completed. This is a first double din unit for me and I am still loving it more n more I use it, so having the added bonus of nav must really hit it for you:D

Did you remove the plastic panel or will that still be in with the enclosure? I ask cuz I have seen it done both ways.

we are planning a similar job in my buddy's jeep grand Cherokee, using the rear quarter and getting messy with glass.
 

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Discussion Starter · #13 ·
Yes I will be cutting a hole in the plastic and then building a simple wood enclosure wrapped with textured vinyl. We'll see how it turns out. Time will tell.
 

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Sweet should look good.

I used vinyl on my current set up, you planning on using any foam under it? I went with 1/4 in foam under it, looks good and it rounds off the corners, just an idea if you havent already planned on using it
 

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Discussion Starter · #15 ·
No I didn't think of doing that but sounds like a good idea. do you have any pictures of your box. Where did you get your vinyl from?
 

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Discussion Starter · #18 ·
Nope, I haven't had a minute to try the ground relocation. I was thinking of going and purchasing a new cheap amp to test with and then return it. The other thing I can do but will have to wait, is get it bench tested. I don't want to wait!! lol You know how it is!?
 

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Discussion Starter · #20 ·
WOW!! that looks really nice. My enclosure will be much smaller so I can keep nearly all the back open.
 
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