I have a '91 Regal, and have an issue with the stereo. I am posting it here b/c I haven't recieved any responses in the regal forum.

the stereo works great...until you turn the motor on. you can hear a buzzing from all 4 speakers with the motor running. As throttle increases, the pitch of the buzz increases. The buzz doesn't get louder with the volume, so it can be drowned out if you have the stereo loud enough.

The tape deck only plays sound for the right side speakers. Occationally, for no apparent reason, it will play both right and left sounds for a second or two.

The five band equalizer only has the top and bottom bands working. The middle three don't show up on the indicator, and don't even change the sound any.

Is the amp bad? I think the tape head is just dirty, but am clueless as to why the equalizer doesn't work properly.

the sliders of the EQ are probably dirty. Sooner or later you're gonna have to break down and buy something new, electronics stuff only lasts so long.

I would have thought of that, but the equalizer isn't controlled by sliders. You tap a button to make the selected frequency to increase, and you tap another button to make it decrease. It has an led indecator to indicate the level each frequency is at.

I guess it would help it I described the stereo. It has three separate units. The amp is under the glove box, the tape player and eaqualizer are on the bottom of the dash, and a head unit is above the tape player unit. Head unit is fine.

The only problem is the buzz noise, and the middle channels on the equalizer don't do anything. I got the stereo out of a junker, as I didn't have anything in it before. I actually am not bothered too much by the inoperative equalizer, as the buzz is the most annoying. Any input on the buzzing would be helpful.

could it be being caused by a faulty coil pack? Does it seem to happen worse if the engine is at higher rpm's? it may be a bad amp. I dont know. Check all connections, especially the grounds.

It doesn't get any louder with rpm, but the frequency-pitch gets higher.

Just thought of something. The person who owned it before me had an aftermarket stereo in it. Could they have had to re-wire anything other than the speakers? Perhaps the big red cable going into the trunk runs too close to something under the hood, and very close to a ground or power lead. I left the aftermarket wiring in in case I decided to use them. They are not connected to anything. The big red cable goes to the pos. terminal on the battery, but the fuse was taken out so that shouldn't be doing anything.
Is it something common to put a switch in the dash to turn an amp on or off? Cause there is a switch in the dash, and a wire somebody put in the fuse panel that goes to something under the dash, which coincidentally so does the switch. Maybe if I push the button to turn the switch on the noise will filter out?

it sounds like alternator noise, what kind of amp is it.
how is the amp receiving power? High level imputs, H.L.I. to a Line out converter, or RCAs?

the amp is the stock amp, and unless they alter the stock wires for it it gets power however the standard way is for stock systems.
I guess a visual would help. These are very basic diagrams.

For the Regal:
12v+...speakers...pow. ant., dim...Grnd
...\....||||||||..../....../....../....../
.....\..||||||||../....../....../....../
.......\||||||||/....../....../....../
.......||||||||||..../....../....../
.......||||||||||../....../....../
.......||||||||||/....../...../
.......|||||||||||..../..../
.......|||||||||||../.../
.......|||||||||||/../
.......||||||||||||/
......|.connector.|...ant lead
.......~~~~~~~.../
............stock amp
..............|.|.|
............./..|..\
.........../....|....\
.......head,tape,equ

Typical:
12v+...speakers...pow. ant., dim...Grnd
...\....||||||||..../....../....../....../
.....\..||||||||../....../....../....../
.......\||||||||/....../....../....../
.......||||||||||..../....../....../
.......||||||||||../....../....../
.......||||||||||/....../...../
.......|||||||||||..../..../
.......|||||||||||../.../
.......|||||||||||/../
.......||||||||||||/
......|.connector.|...ant lead
.......~~~~~~~.../
........stock stereo


I know that when the aftermarket is put in, they put an adapter on the connector for the stock stereo, and then run a signal from that radio to an amp for the subs, ect. My question is, do they put anything between the connector and where its wires go to? Like, do they alter the wiring for the speakers, or would they leave the stock wires in, and run there own? Do they put an amp or anything to boost power to the connector for an aftermarket?

depends on who "they are" and what "they" did to it.
i still say its a alternator/power problem.

do you have any amps other thatn the internal one?

No, there are no other amps that I am aware of.