golfnstuff

My 86 radio has static 99% of the time AM and FM. My biggest fear was replacing or repairing all 6 speaker amps. But, on occasion, I get lucky and tune in to a station and it's clear as can be. If had back speaker amps, I'd always have static. So, any ideas what might be the problem; Antenna? Tuner? or the reciever behind the breadbox?

FOURSPEEDVETTE

You say you have six speakers in your 86? Is it an aftermarket radio? The stock Bose only had four speakers. The dash pad has two areas for speakers, but I've never ever seen any installed there. The stock power antenna has a ground strap attached to it in the drivers side wheel well. Check the connections there. These were never really that great at being static free. You can eliminate some, but not all of it.

martymcfly

My Bose does the same thing, but the clock looses time. I was thinking about replacing it with a Bose cd deck from a camaro. The local wrecking yard will sell one for $35. I found this link on youtube.

Cliff Harris

That's because you didn't look at a car that doesn't have a Bose. Mine has a Delco radio and there are speakers in the dash pad, none in the doors:



The original poster's symptoms indicate bad electrolytic capacitors in the Bose amplifiers. The electrolyte dries out over time and the capacitors stop working.

It's fairly simple to replace the electrolytic capacitors with tantalum capacitors and the problem will be gone forever. Experience with reworking PC boards, i.e., removing and soldering parts is required.

FOURSPEEDVETTE

[QUOTE=Cliff Harris;1583003081]That's because you didn't look at a car that doesn't have a Bose. Mine has a Delco radio and there are speakers in the dash pad, none in the doors:

I didn't realize this. I never noticed a Delco radio setup in a C4. I gotta get out more!

AGENT 86

I'm leaning towards the head unit. There is no separate tuner behind bread box, everything is in the head unit.
Try moving the sliders and dials to see if static gets better or worse.
FWIW, here is the radio schematic from my 86 service manual.

http://dankai.shawwebspace.ca/asset/...2155/radio.pdf

golfnstuff

Lots of good info. Thanks. As for do I have six speakers, maybe not. I assumed there were speakers in the dash but you are probably correct about being a "place" for speakers. Turning the tunner doesn't seem to make things better or worse. I'm leaning towards the poor ground on the antenna since on rare occasions, the sound is clear and maybe that's when it makes good ground. As for the bad capacitors; if that's the case, wouldn't I never get clear sound? There, I think I covered most of the questions asked in your responses. Keep them coming. As soon as it warms up a bit, I'm going after the antenna ground first since that's the easiest. But today it was 8 degrees and even though it's garaged, it's not a heated garage.

pmihaltian

Thanks, that's a good tip.

How about posting some how to "Cliff" notes and photos so we can figure out how to do this improvement ourselves.

Dynamo6969

my dad had the same issue for a while after he got the head unit switched to a more modern one. the idiots at best buy or where ever didnt hook the antenna back up to the head unit. check that first, then go start spending

golfnstuff

Okay, I think I've narrowed down the problem. Since it was sporatic I suspected a grounding problem with the antenna. I think I have a weak ground. When I ran a temporary ground jumper the noise quieted down. Also, while it was quite I found that turning the Bass adjustment caused a "lot" of static. That might be the biggest source. So my plan is to clean up the ground connections and the antenna mast and also start looking at a more modern replacement stereo unit. And no, I don't have six speakers, just four. My mistake. There are none in my dash or at least they aren't hooked up if they're there.
Thanks again for the help and if anyone has any addition suggestions, I'm still listening.

DinoBob

It's not the amps. Cassettes play fine I assume? If you do not know what a cassette is I can send a pic. :-)

Cliff Harris

The main difference between a Bose system and a "regular" radio is that each speaker has its own amplifier in the enclosure.

When I was shopping for my '86 I listened to both the Delco and the Bose. My untrained ears couldn't tell the difference and I figured any differences would be even less important at highway speeds with road noise, wind noise, squealing passenger noise ;-), etc. I didn't think the Bose was worth the extra cost so I ordered my car with the Delco radio.

Since I don't have a Bose system, I don't have a "subject" to experiment with. However, there is this article, which seems to be pretty old as the photo links are broken and they talk about buying the capacitors from Radio Shack (I don't think they still sell electronic components), but you should be able to get them at an electronics parts store.

https://www.corvetteforum.com/articl...se-Amp-Fix.php

http://www.corvettefever.com/techart...s/viewall.html

DinoBob

I believe that the OP is saying that the issue is related to his radio reception, rather than an issue with crackling/popping/noise through the speakers.

Gotta have love for an original owner 86! Impressed.

golfnstuff

Unfortunately it won't accept a cassette. That was my first thought when it came to trouble-shooting but I couldn't get past trying to insert one; no go.
I not only know what a casset isI remember when 8 track was introduced. Been around a while.

martymcfly

They were so cool, especially when they would change track in the middle of a song.