86 Bose radio question
Thread Starter
Burning Brakes
Joined: Oct 2007
Posts: 1,093
Likes: 33
From: Morristown TN
86 Bose radio question
please forgive me if this has already been covered. I have looked and could not find an answer to this.
My 86 has a factory Bose system in it. When it is on and the car in running the rear speakers have a high pitched hum. They also pop when the signal lights blink.
I have had it to 3 Radio shops and they all agree the Bose system is crap and I would be better off stripping it out and installing an aftermarket system but they also say that it would be a pain to do.
one of them said the amps were going bad, another said the alternator may be going out, the other was at least honest and said he had no clue but offered to install a filter but he did say he doubted it would help.
Has anyone had this problem? if so how did you fix it?
I would rather leave it as original as possible which means keeping the Bose system.
My 86 has a factory Bose system in it. When it is on and the car in running the rear speakers have a high pitched hum. They also pop when the signal lights blink.
I have had it to 3 Radio shops and they all agree the Bose system is crap and I would be better off stripping it out and installing an aftermarket system but they also say that it would be a pain to do.
one of them said the amps were going bad, another said the alternator may be going out, the other was at least honest and said he had no clue but offered to install a filter but he did say he doubted it would help.
Has anyone had this problem? if so how did you fix it?
I would rather leave it as original as possible which means keeping the Bose system.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
If the squeel's pitch moves up and down with engine rpm , then you likely have a poor battery cable connection. Even if you don't it won't hurt to clean your connections and it isn't hard. Remove the battery cables (neg first) and clean the cable lugs, bolts, and battery terminals and replace the cables (neg last). You can also prove that it is the alternator by unplugging the alternator with the engine running and see if the squeel stops. If you still have the problem, then you have a common problem with the speaker amplifiers. There are amplifiers at each speaker and the electrolytic capacitors in the amplifiers dry out with age and their capacitance decreases causing the hum. You can remove the amplifiers and replace the electrolytic capacitors yourself if you are handy and your radio will perform like new without hum or sensitivity to turn signals, brake lights etc.
Corvette Enthusiast
Joined: Oct 2007
Posts: 6,795
Likes: 2,711
From: So. Cal.
2025 C7 of the Year Finalist- Unmodified
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Bose
Bose is junk. You can buy a new unit that is made to fit in that spot perfect. Im getting ready to throw my bose cassette in the trash and get a new unit. 89 vert. 
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
You might try replacing the BOSE speaker relay. Is there any popping noise or does one or more speaker quit on occasion? Noises like you describe can be traced back to a bad relay.
The relay is not expensive ($20) but it is a PITA to get to. It's on the passenger side of the dash, above and to the right of the radio. You have to remove the trim from the driver's side of the dash, then the center trim panel.
Remove the radio, the DIC, and the pieces behind that. The relay will be on the lower right side of the "box" that holds the chime generator and starter enable relay.
Look thru the hole on the right side of the box and you should see it. The relay sits in a bracket held by two sheet metal scres which are not fun to remove. Once you get it loose, simply swap the relay and stuff it back among the wires. Don't bother to try to replace the screws!! Small hands help a bunch here
The relay is not expensive ($20) but it is a PITA to get to. It's on the passenger side of the dash, above and to the right of the radio. You have to remove the trim from the driver's side of the dash, then the center trim panel.
Remove the radio, the DIC, and the pieces behind that. The relay will be on the lower right side of the "box" that holds the chime generator and starter enable relay.
Look thru the hole on the right side of the box and you should see it. The relay sits in a bracket held by two sheet metal scres which are not fun to remove. Once you get it loose, simply swap the relay and stuff it back among the wires. Don't bother to try to replace the screws!! Small hands help a bunch here
Thread Starter
Burning Brakes
Joined: Oct 2007
Posts: 1,093
Likes: 33
From: Morristown TN
I cleaned the cables very good and the noise is still there, it does not do it when it is not running only when the engine is running.
The alternator looks to have been replaced not long ago, i did not try unplugging it yet.
I have also noticed that at night the dash lights will sometimes slightly dim and brighten when the car in running. (they do this with the engine at a constant highway speed) the headlights may also be doing this but I will have to wait toll i can have her follow me down the road in it at night and see if I can tell any difference. I am hoping the alternator is going bad because it will be cheaper and easier than working on the Bose system.
i can not find anyone around here that wants to touch the radio. As soon as they see it is a factory Bose they say they would rather not work on it unless it is to strip out the whole system and install a new one.
Thanks for all the help. Looks like I am going from easiest to hardest until I figure it out. Alternator 1st, then the amps and lastly the relay under the dash.
The alternator looks to have been replaced not long ago, i did not try unplugging it yet.
I have also noticed that at night the dash lights will sometimes slightly dim and brighten when the car in running. (they do this with the engine at a constant highway speed) the headlights may also be doing this but I will have to wait toll i can have her follow me down the road in it at night and see if I can tell any difference. I am hoping the alternator is going bad because it will be cheaper and easier than working on the Bose system.
i can not find anyone around here that wants to touch the radio. As soon as they see it is a factory Bose they say they would rather not work on it unless it is to strip out the whole system and install a new one.
Thanks for all the help. Looks like I am going from easiest to hardest until I figure it out. Alternator 1st, then the amps and lastly the relay under the dash.
Safety Car
Joined: Jan 2006
Posts: 3,566
Likes: 4
From: Mt Laurel NJ
St. Jude Donor '06-'07
Gentlemen,
There is a dedicated Audio section on the forum, that is were this question needs to be asked.
To the OP, please go to the Audio section and read the C4 FAQ, it will answer all of your questions.
Randy
BTW, your problem is that the amp's are going bad, best thing to do is disconnect them until you get them fixed or replace them. Read how in the C4 FAQ.
There is a dedicated Audio section on the forum, that is were this question needs to be asked.
To the OP, please go to the Audio section and read the C4 FAQ, it will answer all of your questions.
Randy
BTW, your problem is that the amp's are going bad, best thing to do is disconnect them until you get them fixed or replace them. Read how in the C4 FAQ.
Last edited by RandyJ75; Oct 29, 2007 at 12:51 AM.
Thread Starter
Burning Brakes
Joined: Oct 2007
Posts: 1,093
Likes: 33
From: Morristown TN
sorry about posting in the wrong section originally but I did not even know there was an audio section.
I always just clicked on the C4 section.
Now back to the radio question.
last night the noise stopped, I am pretty sure I let off the brake and it stopped. a few minutes later it started back on its own.
I was on a sorta rough road so I am thinking something is loose somewhere.
Any tips on where to start?
I always just clicked on the C4 section.
Now back to the radio question.
last night the noise stopped, I am pretty sure I let off the brake and it stopped. a few minutes later it started back on its own.
I was on a sorta rough road so I am thinking something is loose somewhere.
Any tips on where to start?
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