C4 Bose question - ZR-1 Net Registry Forums

Route 66 · 09-11-2022

I took my 93 C4 out for a drive today. I could not get any sound out of 3 of the speakers . I tried everything I could think of nothing worked. [Need to add this car sets a lot] When I drove it about 2 months ago they worked okay. Has anyone had this type of problem. If so would you tell me what to look for. Thanks Your help would be most appreciated.

jw63 · 09-11-2022

Bad amplifiers

Sent from my iPhone using ZR-1 Net Registry

mlipmd · 09-11-2022

Numerous threads on here and the Corvette Forum - Most likely the capacitors in your 29 year old speaker amplifiers have leaked from age and need to be replaced. Hopefully it's just the caps and not damage to the amps themselves because of the leaking. It has nothing to do with use, just the age of these things.
There are numerous places to repair these - Dr. Don's, Bose Central, carstereohelp, etc, just search online and you'll find them.
You will have to remove the speakers, then the amps from them, and send them out for repair, and carsterohelp has some videos on this or look on YouTube. Cost ranges from $49/amp for BoseCentral to $99+/amp for the others.
Hopefully it's just the caps in the speaker amps that need replacing and not the ones in the CDM box (look it up) because then that will have to be removed and sent out as well.
Call one of those guys first to talk about your problem, they are all very willing to help. They are the experts, much better than your local stereo repair shop.

Route 66 · 09-11-2022

Thank you I did not know where to start. l WILL DO more research before I Do A TEARDOWN.

Matt B · 09-12-2022

From my own experience I strongly suggest you consider removing all components and have them fixed. "If it ain't broken don't try to fix it" can become an expensive trap here.
As it was mentioned it's not a question IF your capacitors will leak, just WHEN. Leaking capacitors spill acid all around them which may cause a lot of damage to the circuit board or other components.

In my case there were bad capacitors in all 4 amps (on of them was so badly damaged that no repair was possible), the CDM box and the head unit.
Head unit was still working but already damage invisibly from the outside.

So... as a precaution I'd pull all those components and have them at least checked. It's more effort on the spot but bundles all components in one "downtime". And it mitigates futures risks.

Pulling the CDM is not as bad as it seems as you can work on it from the side (from below the fuse holder). It's still a PITA job but doable.

I know not everyone will agree to my all in one shot approach but personally I'd choose this approach for every upcoming C4 with bose that joins my garage.

Young1 · 09-12-2022

I agree with Matt and have done the same. I used Factory Car Stereo Repair Inc in Lake Mary FL. I set appointment with Bob and drove to his location. He tested and looked at all components quickly and I left him the ones needing repair.

Figure8it · 09-12-2022

Marc Haibeck also offers this service (I had mine done when my car was there). Not sure about the cost compared to others but I know it?s done correctly.

1992 Polo Green ZR-1, DRM500

bowtiguy · 09-12-2022

I agree w/ Matt. Do it all at once. I've had two complete systems done. Bob @ Car Stereo repair was $300-400 cheaper than Dr. Dons. Both systems sounded great once completed & installed!

09-11-2022	#1
Route 66 Join Date: Dec 2006 Location: Paris Texas Posts: 182	C4 Bose question I took my 93 C4 out for a drive today. I could not get any sound out of 3 of the speakers . I tried everything I could think of nothing worked. [Need to add this car sets a lot] When I drove it about 2 months ago they worked okay. Has anyone had this type of problem. If so would you tell me what to look for. Thanks Your help would be most appreciated.

09-11-2022	#2
jw63 Join Date: Dec 2019 Location: Indianapolis, IN Posts: 45	Re: C4 Bose question Bad amplifiers Sent from my iPhone using ZR-1 Net Registry __________________ '90 #413 Red/Red Sold '90 #1583 Red/Red

09-11-2022	#3
mlipmd Join Date: Mar 2021 Location: Crawfordville, FL Posts: 220	Re: C4 Bose question Numerous threads on here and the Corvette Forum - Most likely the capacitors in your 29 year old speaker amplifiers have leaked from age and need to be replaced. Hopefully it's just the caps and not damage to the amps themselves because of the leaking. It has nothing to do with use, just the age of these things. There are numerous places to repair these - Dr. Don's, Bose Central, carstereohelp, etc, just search online and you'll find them. You will have to remove the speakers, then the amps from them, and send them out for repair, and carsterohelp has some videos on this or look on YouTube. Cost ranges from $49/amp for BoseCentral to $99+/amp for the others. Hopefully it's just the caps in the speaker amps that need replacing and not the ones in the CDM box (look it up) because then that will have to be removed and sent out as well. Call one of those guys first to talk about your problem, they are all very willing to help. They are the experts, much better than your local stereo repair shop.

09-11-2022	#4
Route 66 Join Date: Dec 2006 Location: Paris Texas Posts: 182	Re: C4 Bose question Thank you I did not know where to start. l WILL DO more research before I Do A TEARDOWN.

09-12-2022	#5
Matt B Join Date: Jan 2021 Location: Beautiful Bavaria Posts: 523	Re: C4 Bose question From my own experience I strongly suggest you consider removing all components and have them fixed. "If it ain't broken don't try to fix it" can become an expensive trap here. As it was mentioned it's not a question IF your capacitors will leak, just WHEN. Leaking capacitors spill acid all around them which may cause a lot of damage to the circuit board or other components. In my case there were bad capacitors in all 4 amps (on of them was so badly damaged that no repair was possible), the CDM box and the head unit. Head unit was still working but already damage invisibly from the outside. So... as a precaution I'd pull all those components and have them at least checked. It's more effort on the spot but bundles all components in one "downtime". And it mitigates futures risks. Pulling the CDM is not as bad as it seems as you can work on it from the side (from below the fuse holder). It's still a PITA job but doable. I know not everyone will agree to my all in one shot approach but personally I'd choose this approach for every upcoming C4 with bose that joins my garage. __________________ ZR-1 #638/1991

09-12-2022	#6
Young1 Join Date: Sep 2016 Location: Ocala, FL Posts: 901	Re: C4 Bose question I agree with Matt and have done the same. I used Factory Car Stereo Repair Inc in Lake Mary FL. I set appointment with Bob and drove to his location. He tested and looked at all components quickly and I left him the ones needing repair. __________________ Steve Young 1991 ZR-1 Quasar Blue Metallic/Black #729 Second Owner 1991 ZR-1 Dark Red Metallic/Black #2040 SOLD 1990 ZR-1 Dark Red Metallic/Saddle #1670 SOLD Double your happiness.....complain half as much.

09-12-2022	#7
Figure8it Join Date: Nov 2021 Location: Mokena, IL Posts: 82	Re: C4 Bose question Marc Haibeck also offers this service (I had mine done when my car was there). Not sure about the cost compared to others but I know it?s done correctly. 1992 Polo Green ZR-1, DRM500

09-12-2022	#8
bowtiguy Join Date: Aug 2005 Location: Cali-rodo Posts: 262	Re: C4 Bose question I agree w/ Matt. Do it all at once. I've had two complete systems done. Bob @ Car Stereo repair was $300-400 cheaper than Dr. Dons. Both systems sounded great once completed & installed! Last edited by bowtiguy; 09-12-2022 at 12:53 PM.