Engine whine through radio

[91Regalsaloon]

Good morning. I have been having an on going issue with my 91 Regal with a 3.8. The radio "whines" with my engine RPMs. I have new AC Delco plug, wires, and coils. Is this a common problem with older cars ? I do still have the factory radio and such.

 

Thanks

[Psych0matt]

There is probably a bad ground somewhere. I have this in one of my aftermarket stereos, and it seems to go with the stereo (ive had it in 2 or 3 cars). I'd check all your wires at the harness for the stereo, and then make sure all your grounds for the electrical system are good

[55trucker]

Hmmmmm.....is it a *red* whine or a *white* whine?

 

Im partial to chardonnays personally...:new_all_coholic:lol

 

 

 

ok, getting serious now....

 

read thru this link from Crutchfield, it is informative, as well another good link that is more involved where after market systems are concerned but the basics still apply,

 

after installing an aftermarket receiver I noticed a pitch varying whine (alternator) thru the fm tuner as well the cd player, ended up installing a filter before the receiver to kill the annoying situation (it probably is a ground loop problem but the filter stopped it).

 

A replacement alternator that was installed near the same time that the whine started may also be in the mix.

 

http://www.crutchfield.com/S-dyNEhuKIv9L/learn/learningcenter/car/noise_suppressors_installation_guide.html

 

 

http://www.termpro.com/asp/pubs.asp?ID=121

Edited February 27, 2014 by 55trucker

[tazman11683]

make sure antenna ground is good

[Night Fury]

Mine had this problem and it was the factory amp behind the glovebox

[Addicted2bass]

Try re-grounding the radio, and factory amp if it has one. If that doesn't fix it then either your alternator is on it's way out, or more than likely the radio/amp is bad.

[RobertISaar]

assuming the alternator's rectifier diodes are okay(not producing AC current), i could pull up the GM procedures, there are a couple of suggested fixes, most are cheap/simple.

[Booba]

assuming the alternator's rectifier diodes are okay(not producing AC current), i could pull up the GM procedures, there are a couple of suggested fixes, most are cheap/simple.

 

If you don't mind, I'd like that. I have been chasing my whine for about 2 months now, and the majority ended up being my bad alternator. With the new one I still have it, but it's maybe 10% of what it used to be.

[RobertISaar]

these may be of use....

 

there are other pages/procedures(especially when going around to different years), but this should apply to your car.

 

http://imgur.com/0ejGaMQ,DMYIBBu,nfFWooE

[Booba]

So I should check that ground? (1)?

[Imp558]

Why don't you unplug the alternator for a minute and see if it goes away all together? Then you're probably after a ground, try wiggling stuff around under the dash too, low tech troubleshooting first solves many problems.

[RobertISaar]

So I should check that ground? (1)?

 

among the stuff listed on the other 2 pages, yes. in fact, all of the grounds are suspect when whine occurs.

 

Why don't you unplug the alternator for a minute and see if it goes away all together? Then you're probably after a ground, try wiggling stuff around under the dash too, low tech troubleshooting first solves many problems.

 

there is a pretty neat "noise sniffer" procedure that involves a chopped up piece of radio antenna to find sections of wire that are generating EMI, you plug it in place of the actual antenna and basically use it like a wand around suspect wiring.

[Imp558]

 

there is a pretty neat "noise sniffer" procedure that involves a chopped up piece of radio antenna to find sections of wire that are generating EMI, you plug it in place of the actual antenna and basically use it like a wand around suspect wiring.

 

That's neat! I've never seen one of those. I did have a handheld test amp I made from 2 LM386 IC's that inadvertantly would sniff RF. I suppose an early handheld "Transistor Radio" from the 80's would do that too. I should have patented that application for my crappy little test amp back in 1991, another missed opportunity.

[Booba]

Lol, good ideas. I've been chasing this with different RCAs, new grounds at the amps, battery, and alternator, RCAs are run away from all the power wires, and grounding the head unit to various locations (the battery, the dash, the factory location, the same location as the crossover and speaker (not sub) amp, I've been everywhere with it)l. My alternator ended up finally going out, making my car appear possessed during the process. Now that I've put the new Alt in, the whine is 10% of what it used to be, if that. I'm gonna pick up some shielded RCAs to go from the crossover to the amps, and route the head unit's power to the same spot as the amps (battery post)...along with some of the stuff on those 2 pages, lol.

Edited April 18, 2014 by Booba

[Imp558]

Seriously? Aftermarket stereo would have been useful information in the title or first post.

[Booba]

Not my thread...I have another thread in this section, I just saw this thread was bumped and was a similar issue to what I am experiencing. Didn't mean to offend, Geez.

[RobertISaar]

http://imgur.com/bmljmQo

 

noise sniffer.

[Imp558]

Not my thread...I have another thread in this section, I just saw this thread was bumped and was a similar issue to what I am experiencing. Didn't mean to offend, Geez.

 

I see that now, jumped the gun a bit. It's important to have all the pieces when working on a puzzle. There's this thing that happens when you work on cars professionally, you spend a long ass time diagnosing and chasing problems and once you find it the customer says something like "Oh, that makes sense, this one thing happened to that part just before the problem started". It's really frustrating because had they started my day with "This one thing happened and now this condition exists" I would have started there. Needless to say, I start every service call sitting down and talking now.

[gp1991]

i had this same problem on my car, i just got a radio from a 93 grand prix and put it in the old radios place and that radio did not have the same issue. Must have been something internally within the radio idk.

[RobertISaar]

possible, likely even.

 

if the radio power supply didn't have any type of filtering on the +12V circuits, that would be stupid, GM engineers know better than that. i get the feeling that part of the filtering process had worn out(dryed-out electrolytic cap, for instance) in the one that hasn't yet in the other.

 

a 91 was put together using parts made in 1990.... that's 24 years old now, that is a long time for an electrolytic capacitor to be in service in an area that can reach some fairly hot temps. even if it hasn't failed, i would expect it to be out of spec.

[04gt]

i had the same problem but only after i ran rca cables over my alternator when insttalling my system, moved it and gone, weird everythings original in your car