jd_black_00

Hi guys, I've got a 2000 Corvette Coupe. It's highly modified, but the stereo system is all stock. Recently my system lost all base and the ability to adjust the base. I did some research, checked fuse #28 in the footwell and sure enough it was blown. I replaced it, fired up the stereo and again, no base. That fuse blew as well immediately. Is the only possibility a short in the wiring somewhere? Thanks in advance for your help!

4XLR8N

Excessive current flow (amps) is what blows fuses.

Given that the max voltage in the system is constant, the only variable is resistance. When resistance is reduced to a point that current flow exceeds the fuse's rating, it blows. This is almost always caused by a short circuit (assuming the circuit has not be messed with by putting lower resistance components in it).

Finding a short can be a bear. It can also cost a lot of fuses in the process. It's pretty much a process of elimination.

I don't have a circuit diagram in front of me, but a good start would be to pull the output wiring from the radio and then install a new fuse. If it blows, the problem is either the radio itself or upstream of the radio. Unplug the power input into the radio - does fuse still blow? If so, it isn't the radio - it's upstream. If the fuse does not blow with the radio plugged into power, one by one reconnect output circuits to the radio. When the fuse blows, you have found the guilty circuit. Now you have to hunt down where the short is. Unplug the component at the end of that circuit and install a new fuse. if it blows, the problem is in the wiring. If it doesn't blow, the problem is in the component.

A wiring schematic will be very helpful as the above description is pretty generic, but it gives you the basic approach to take.

Good luck! Post up your findings...

73Corvette

If I were in your shoes... I would give Dennis at Double D a shout...you come back and tell us what you learn there buddy...

jd_black_00

Thanks guys! Currently helping my Dad recover from surgery but I'll tear the interior apart in a few weeks and report my findings

dadaroo

Fuse 28 is for the Bose speakers and not the radio. I can pull the schematics later and tell you where to start in diagnostics. Not at home now. May be a day or two, I have several irons in the fire right now.

The front door amplifiers need to be powered.

I assume you are still getting some sound from the rear speakers? They are fed by the radio.

73Corvette

Like dadaroo said on another thread, and the reason I say call Dennis is that he has probably "been there done that" and can point you in the right direction... then if you need an electrical expert you can contact dadaroo for further clarification.

dadaroo

I looked at the schematics and that fuse only feeds the amps in the doors.

I would first pull the fuse and see if the circuit is grounded somewhere. If you need help on this just PM me with your number and I can explain.

If not, then I would remove/pull back the door accordion on one of the doors and unplug the harness. The connector is in the A-pillar and can be pulled out to disconnect.

I doubt that both amps are the problem, should just be one.

Here is a link on the accordions and connectors.

https://www.corvetteforum.com/forums...-there-is.html

jd_black_00

Hey,

Sorry it took me a while to get back to you, been helping my dad recover from hip surgery. Here's all of the details I know:

All four speakers emit noise, but no base from any of them. Treble adjustment works for all 4. The fuse #28 blows whenever I put one in. I currently have no fuse in there, the speakers all work without bass. Is your suggestion to unplug each side independantly and try it with a new fuse in place? I can go run to the store and pick up some more fuses if necessary!

73Corvette

Have you called Dennis and told him what is going on?

jd_black_00

I left him a voicemail

73Corvette

Sorry I am a little OCD... thanks for calling him, he'll no doubt call you back. I just think sometimes it's quicker, simpler, easier to just touch base with an expert... he has probably seen this before and may know exactly what you're issue is and can give you the correction. Or, he may not have a clue and dadaroo can work his schematic magic and help you find out whats going on.

dadaroo

Yes, we need to figure which door speaker is shorted to ground. If you know how to use a ohmmeter you could just do a check at the door connector to see which one was shorted. I could tell you which pin to check.

jd_black_00

Great, I'll do that today. It's probably on the driver's side, as I had that whole door apart this winter. Can you please tell me which pin to check?

dadaroo

Each door connector for the speakers uses the 10 cavity connector in the accordion of each door. Fuse 28 feeds the ONLY pure Orange wire in each door. There is an Orange/Black wire which is NOT the one you want.

There are 2 ground wires coming out the door in each connector. They are Black/White wires. Rather than try and tell you which one is specific to the amp I would try each one to test.

I would disconnect the connector and measure resistance from the Orange wire to both ground wires on the DOOR SIDE of the connector. If you get 0 ohms on one or both you have found your problem. If not, then measure the resistance on the other side of the connector and you should get 0 ohms.

I would then go to the other door and do the same. We want to confirm the short is inside a door or in the car wiring. I think it is inside a door.

Let me know if you have any questions.

Mr. Sam

PS: If you feel like we need to discuss on the phone just PM me your number.

jd_black_00

Hey Sam,

I just went out and spent some time investigating the problem. Since I suspected the driver's side amp to be the problem, I went ahead and threw in a new fuse and disconnected the connector from the driver's side. I fired up the stereo and sure enough, I was getting bass out of the passenger's side speaker. When I take the car back to New Jersey next week I'll go ahead and tear apart the driver's door and inspect the wiring and the amp itself. Thanks for all of your help!

dadaroo

Excellent. Let me know if I can help further. Keep us informed.

I figured it was probably one of the amps, but which one? Looks like you found it.

Let's just make sure it is not a wiring short in the left door and not the amp. Trust but verify.

jd_black_00

So I pulled the door apart today, wiring was fine, so I swapped the speaker. Everything works great now! Thanks for all of your help

dadaroo

Great. I assume you mean you swapped out the whole unit and not just the speaker? Just so everyone knows.

jd_black_00

yes, swapped out the whole unit. Might dissect the old one in the future to see if I can figure out what failed

dadaroo

Should be easy to find in the amp. The speakers should still be good even if you don't fix the amp. You can verify if they are good with just an ohmmeter reading across the coil of each.