LSMAC

I have the kenwood dnx9980HD nav unit. When I cut the car on I get no sound from the speakers at all. No chimes, beeps or anything. I don't get any sound from the speakers at all. I would appreciate any help from you guys. I try to always research before I post a help thread anywhere. I am a rookie with electronics.


When I bought the car 2005 Base, the owner said that the system worked fine until he changed a starter recently because the radio kept draining the battery (he didn't change the battery first i'm assuming). So far I have purchased a new amp assumiing after researching for days that I just suffered the common overheated amp issue. That wasn't the case, so now I have to figure out the real issue. I am not fluent with electronics much at all!! I bought a digital multimeter and don't really know how to use that either but I will do some research and figure it out.

Do I need to pull the radio console apart and get behind the radio?

Where do I need to look at to see the speaker's trigger wire? Where is the central junction (I imagine there is a wire that comes out of the amp that power the speakers or something)

My multimeter is a innova 3306, is anyone familiar with this model?

Thanks in advance guys.

1bdvet

Trying contact Dennis at Double D for help, he's the expert on Corvettes and concerns, he is also vender here with lot of knowledge.

http://www.doubledmods.com

markcz

Does the radio power up and let you change source/channel, or is it completely dead?

Aftermarket amp or stock?

Source of info for "overheating amp" diagnosis?

C6 radio prints are HERE

Check/replace the AMP fuse under the hood if radio powers up.

Check/replace the RDO/S-BAND/VICS fuse in footwell if radio is dead.

The radio itself generates the trigger, after it is turned on by the interface adapter. It could be an issue with the interface adapter not passing the trigger from radio to amp. Voltage sholud be found at B3 of the big harness behind radio if it's working properly.

LSMAC

Thank you guys for your input. Sorry I have not been on in a few days. Mark, to answer your questions:

Does the radio power up and let you change source/channel, or is it completely dead? yes, I am able to cut on the radio and use gps, change inputs, go through settings etc.

Aftermarket amp or stock? AMP is the oem Bose amp

Source of info for "overheating amp" diagnosis? Not really much of a source lol. I swore I found a few threads of bad amps before posting this. Here is the one I saved in my favorites as a reference for later: https://www.corvetteforum.com/forums...-no-sound.html

C6 radio prints are HERE

Check/replace the AMP fuse under the hood if radio powers up. I replaced the fuse under the hood as well as near the amp just to be sure.

Check/replace the RDO/S-BAND/VICS fuse in footwell if radio is dead.

The radio itself generates the trigger, after it is turned on by the interface adapter. It could be an issue with the interface adapter not passing the trigger from radio to amp. Voltage sholud be found at B3 of the big harness behind radio if it's working properly.

I will be honest, I think my eyes started spinning when looking at the pinouts. I am prideful so I will give it a shot and pull the radio so I can check the power. What position should I be setting my multimeter to when checking the power to b3?

markcz

One more long-shot question.... Can you hear anything when radio is playing FM radio band, but hear nothing on other sources?

You really don't need to look at the prints at this point.

Take the dash console off and pull the radio out, but leave it connected. Turn radio on to a source that is clearly playing music, turn volume up. Put the meter on DC volts, black lead to metal frame in car, red lead to wire at B3 of biggest plug behind radio (pins are labeled on plug as A1-12 and B1-12, but it's a white wire third from the end). If it's working properly, meter should show 12v. It may be tough to get at the pin depending on the size of your meter leads, but a straightened out paper clip attached to the lead should fit fine.

Assuming you DO NOT have 12v at B3, put red meter lead on blue or blue/white wire coming out of the radio wires and connecting to the interface adapter. If you DO have 12v on the blue wire, then you just need to bypass the interface with the amp trigger.

LSMAC

Ok, so I took some pictures of the back of the radio and various connections so I can be sure we are on the same page. I see the biggest connection on the back of the radio is the amp power connector. If that is the right plug, the third wire isn't white. I did see a white and blue wire that has a splice in it. I tried to measure the connection but didn't get anything on the meter. I figured I wasn't finding a good ground location. I was trying to use the door hinge on the D/S. There are some other things like the Onstar/Amp device that seems to be something like a junction point. I will post pictures so you can get a better idea of what I am trying to explain.

markcz

The B3 wire is only white on the stock harness, I have no idea what color it is on the GMOS harness.

Do this test to make sure the amp fuse is good and the amp is functioning....
With the radio playing a song and the dash pulled apart, use a short piece of wire (12" or so) that's stripped on each end to jumper between the yellow power wire going into the Kenwood and the B3 wire on the GMOS outlet. You should hear music when you have both ends of the jumper wire making contact.

If you still don't hear anything, either the amp fuse is blown, or the amp itself is bad or disconnected.

If you do hear music, here's how to fix the most likely problem...

Find the B3 wire on the GMOS harness (look at the oem plug, it's labeled and the wire is white). Snip the B3 wire a few inches on the interface side of the GMOS plug, also snip the blue/white wire coming out of the Kenwood at the end farthest from the radio (it should currently be connected to the GMOS). Attach the blue/white wire to the B3 wire on the big plug. This will bypass the trigger voltage around the GMOS so the radio is directly triggering the stock amp.

LSMAC

Ok, so I just took another stab at it. First, it appears that every wire you mentioned to diagnose had already been spliced before (some more than once). The B3 on the factory wire (white as you said) comes through the other side as white/blue and is spliced maybe 1" from the connector. It is tied into a blue wire that runs into a relay. From that relay it runs into another splice that is the white/blue wire that goes into the kenwood connection. The yellow power wire that you wanted me to run a jumper to was already spliced and going into the relay as well. The other end looks like it bypasses the GMOS as well. But when I hooked the short jumper from the yellow wire coming out of the kenwood into the white/blue B3 wire connecting to the factory plug, nothing happens. The radio wont even power on. But I hooked the other end (away from the radio that routes to the relay) into the white/Blue B3 wire, the speakers make a static like sound. This is the first time i have heard anything out of the speakers AT ALL since I bought the car. But if I hooked the yellow wire going to the relay, coming out of the kenwood, and the B3 wire together, I get the radio to stay on and the static, but no sound from the speakers. There is definitely a cd in that is playing throughout the testing. I don;t know what kind of chimes the Corvette has so I tried opening the door with the wires connected to see if I would get some other noises from the speaker but there was nothing. I set up my bluetooth and made a call and still nothing.

I still have no luck getting any testing done with the multimeter, I put the dial on DCV 20 as shown in the picture and don't get anything when I tested numerous connections just to be sure. I'm almost sure it's my ground selection but shouldn't the door hinge be a good ground or does it HAVE to be chassis? I also tried to use the seat stud on the passenger side since it is exposed but it made no difference.

Thanks again for your help. I am sure getting the static noise (that is really faint) in the speakers is some sort of a breakthrough, but I am not fluent enough to figure it out.

LSMAC

I finally got the speakers to play audio. I did not trace the wires correctly and was still going into the GMOS. After bypassing this I did get a cd to play. Only problem now is that I believe only one speaker (rear driver side) is playing music. I do feel the rattle an thump from the front door but I have my volume maxed and it is not too loud with the car off. I won't be able to hear a thing while it's on. Guess I may have to buy new speakers of these are blown. Or maybe they have been wired wrong? I tried cycling through each speaker but every location I selected only played the sound through the rear driver side speaker.

markcz

Make sure that all of the wires are connected according to the GMOS Instructions except for the following:

-don't connect the HU blue/white trigger wire to the GMOS, connect it directly to the wire at B3 on the 24 pin plug (doing this eliminates the relay)