Hello guys,

My 1987 corvette coupe is having stereo/speaker problems. None of the speakers are playing any sound from them whatsoever. Although I tested one speaker and it worked so I’m just going to assume that all of them work. Also, I installed a aftermarket radio and it didn’t seem to solve the problem. I’ve been told that if all the speakers stop playing that it’s not an amp problem. What could it be? Someone has told me it could be the CDM? I have no idea where that is located so if someone could point me to how to test it and where it’s located that would be great. I would love to try to work on fixing this myself to save money but if it’s something too advanced then a recommendation to someone would be nice. Thank you for all your help in advance.

 

Have you made sure all fuses are good? If you have interior lights out, that's the CTSY fuse and would affect the radio.
Does power antenna go up and down?
Turn on the radio and wiggle all the ***** and sliders real good
Otherwise it's most likey the speaker amp relay. No fun to get to and find. Google it

 

No sound from all speakers could mean that all four amps are dead. Is this a recent purchase that your trying to sort out the problems or were all four speakers playing and all of a sudden stopped?

 

Actually yes, the door light panels don’t turn on, the inside hood lights don’t turn on, and the a/c doesn’t turn on. I went to a mechanic that I know and he had a tool to put power to specific wires and he put power to a certain one and it turned all those lights on as well as the ac! Is the speaker amp relay behind the stereo dash? I’ve been told all the fuses were good but I can always double check for reassurance. Also, my power antenna doesn’t go up

 

yes, I just got the car a month ago and finally am getting to fix the stereo system, I was quoted about 800-960 to fix all 4 speakers which doesn’t even included purchasing new ones! I don’t believe the problem on my car u I s that serious. I got the car and all 4 never worked. I connected the speaker to an external wire to play it and that’s how I tested it.

 

Your problem is not the speakers.
Change the radio and CTSY fuses to ones you KNOW are good. You can't always tell be looking at them if bad or good

 

Does your radio lights turn on?
like back ground and info area, etc? Then you have all the power you need.
why are you trying to use the bose stuff anyway? Originally, they were trying to eliminate distortion by amplifying the speaker input at the speaker.
the bowes radio does not put out enough amplitude because the amps are at the speakers.

just treat it as a normal car and locate the speaker wires and buy real speakers for it, Bypass the speaker amps and put normal new speakers in it of your choice. those speakers are almost 35 years old!
then get some of your money back and sell the amps here on the forum.
the bose system is great when it works, but it is a system. You can’t just use parts of it

 

Yes the radio light does turn on. I am going to replace the speakers with better 6x9's in the back and 4's in the front but I would think I need to fix the original problem first before replacing the speaker. If I bypass each amp then I would need to buy an external 4 channel amp?

 

You can't throw aftermarket speakers in a bose radio car. They wont work
Just like you threw an aftermarket radio in and expected the speakers to work. They won't
Fix the bose system or completely replace

 

Does your Corvette have the Bose Stereo in it? Each speaker in a Bose system has it's very own amplifier board and they can be rebuilt for a lot less than the $800-900 you were quoted.

It sounds like you are not getting power to your interior. Take a moment and verify the battery voltage and then measure the voltage at the fuse panel. They should be the same, if not the fusible links on your Corvette might have corrosion and that can cause a low voltage or No voltage situation. Mine had close to 2 volt drop between the battery and the fuse panel. I solved it by cleaning the post where the fusible links get their power from. On the 1988 it is behind the battery mounted on a frame rail under the side cover there is a post with a bunch of wires coming to it. One should be a red wire that comes from the battery directly. This point is where the fusible links get their battery power and if there is any corrosion it can affect the voltage downstream. I fixed the post and found my fuses had corrosion on them as well. I replaced the aluminum fuses with new ones and everything inside my Corvette started working normally. Prior to the repair my radio was seeing barely 10 volts power and that was not enough for the Radio to work properly. Afterwards the antenna went up and all the electrical accessories were working like power seats and interior lights.

My 1988 C4 Coupe came with a Bose Stereo but the amp/speakers started failing after a couple years. I removed all the parts and put them in a sealed bag inside of a box so they can be made workable again if someone so chooses to do so.
This is a great point for "New to Corvette" people. I had a good friend who spent a lot of money and bought a beautiful white 1970 LT1 Convertible Corvette and had made many updates but saved the parts in his shed. He died suddenly in an accident in Alaska. When I saw his family clearing out the house they had thrown away thousands of Dollars worth of parts for the LT1 not knowing what they were. I saw the problem and quickly gathered up all the significant parts for my friends family and identified each one and bagged them up. Every significant part I remove I Bag and Tag so if something happened to me my family would not throw away thousands of Dollars worth of Original Corvette parts. I have a 1968 C3 with its big block and I do the same for this Corvette as well. To us these parts are obvious but to an untrained eye they appear as junk. What do you think a working 1970 Corvette Stereo is worth? The LT1 came with many spares and they well being thrown away despite their value. My 1968 came with an AM-FM radio with one mega transistor mounted on a heat sink in the dashboard. That was a big deal back in October 1967 when they built my C3. It has been bagged for over 27 years in my garage as I have owned the Corvette 29 years tomorrow July 19th.

I would suggest you speak with one of the salesmen at Crutchfield as they are really good at installation support. My daughter wanted to drive the 1988 C4 so she started complaining about the stereo. Crutchfield's sold me a $450 package that consisted of a modern radio that had Bluetooth and USB plugs built in. I installed the radio and it looked great and then I removed the factory Bose Speakers to replace them. I too used a 6x9 pair of speakers in the rear and 4 1/4" speakers in the door panels with tweeter mounted on top of dashboard and microphone permanently installed on the drivers visor bottom.

The system works great and sounds nice BUT it is not a Bose system anymore. The original Bose systems when working are "hard to beat" in a C4. If the head unit in your needs work there are companies out there who do that. The amplifier boards if fixed might give you a awesome stereo.

I used the original wiring harness' and even the speaker wires. With a Bose system there were four wires going to each speaker. One pair was the power for the amplifier board and the second pair are for the sound. It was easy to identify which wires were the ones to use IF you have a Factory Service Manual set for your year Corvette. There is no need to re-wire the whole stereo unless you have a 400 watt amplifier driving the rear speakers.

The Crutchfield company and I go back to 1977 and I have bought a lot of systems from them over the years. The after-sales support is "superb" and they will help you find something in your price range and help make it work in your Corvette.
The stereo head unit will need to be changed out to allow the use of a new one. The one I bought had 50 watts per channel (times 4) which is fine for me. The Bluetooth part works awesome and I love the hands free telephone function. It is clearer than some factory hands free systems. Crutchfield supplied all the parts I needed to install the system in my C4 and had techs available to help anytime.

 

The factory Bose systems seems to be a love or hate it situation with most folks (not unlike audiophiles and Bose in general ).

If you want some detailed information on the system, you might want to look at the guide I put together on the topic from all of the information I gathered when restoring my system.

https://www.corvetteforum.com/forums...aux-input.html

As you can see, I'm a fan of the system. Additionally, the fact that these era cars have a DIN 1.5 size radio slot makes aftermarket radio heads tougher to come by without using a filler panel (which doesn't look right to me).

Best of Luck!

 

If you are replacing the bose radio, all you can use is the power wire.
what is so hard about that?
1. You cant use the amps.
2. Speakers are old
3. you cant use anything else from the system if you replace the head unit.
theres nothing to get working if you are not using the bose.
just run new speaker wires, install your new speakers to the new wires!
now if you put the bose back in, you have to check all sorts of stuff.
power
speaker relay
4 amps
grounding
antenna coax and antenna ground.