AUDIO EXPERTS! Very Annoying Alternator Whine through Stereo.

[dephrag]

Ok, for the life of me I can't seem to figure this out...

I have a Kenwood 428 deck hooked to an Alpine F407 amp. The amp is directly connected to the battery + and - which is right beside it in the trunk. The ground cable is shorter than the + and less than 18".

When my car is off, the system sounds fine.. maybe a tiny bit of hiss/distortion which could be normal, but when the car is on, i get a high pitch whine which varies with the speed of the engine. The volume of it does not change however. So cranking the stereo usually masks it.

So from what I read it appears to be a ground loop.. And I don't know what else to do!

So far I've:

Replaced the Deck.Replaced the Amp.Run an ipod through the rca wires the stereo uses to check for bad wires.Tried multiple grounding locations, (Stereo harness, antenna, battery, hole drilled in frame under the stereo.)

If I plug an ipod or device straight to the amp, it gets rid of the whine and distortion. So I thought it was the deck since it was an open model.. but replacing it didn't help.

The RCA's are going to the amp, and i've hooked all the speaker wires on the harness up even though they're not really doin anything..

Now originally the unit wouldn't power on when i connected the ground via the factory harness. Only when a hole was drilled in the frame, or antenna plugged in would it come on. Could my car have some major grounding issues? (Passenger window doesn't work, heat gauge bounces, car stalls after putting clutch in at high revs, alarm acts funky etc)

What I dont get, is if it was coming from the deck or wiring at the deck, would the whine not be amplified by the amp?

VERY CONFUSED!

James

[96qtrip]

How many miles on this beast? Sure it's not igniton whine? Even these lose filtering. But they both sound like a loss of hash filtering

First, on the RCA leads, make sure they are getting a clean grip on thejack; close the four shells and then insert the plug with a slight twist.

Second, check all the unit (deck, rcvr etc connections to power and ground, some units have seperate leads.

Third, loosen, and then pull the alternator, and clean the bolt and mount surfaces of the mount, (4 mating surfaces possibly); if its aluminum, thenuse a brass wire brush as well (like on a battery terminal). Then reattachsecurely

Fourth, check the output volts on the alternator, and the bypass capsif they are attached.

If still no luck, visit your RS store and get these:

.01 ufd, .05 ufd and .001 mfd 50 volt or greater rating, and connectacross the power terminals at the input of each unit.

Report back when you can!!!! and good luck

[xekushnr]

are you using cheap RCAs? it sounds like youre getting noise. borrow some RCAs from a friend and see if it works better. or just reroute your RCAs and see if it makes a difference.

[dephrag]

Well thanks for the quick replys...

The body has just over 250k Miles on it, but I put a SR in it last year. (It's a '95)

I was realllly hopin it wouldn't be anything super complicated. Last time I tried to replace my alternator it was the worst experiece of my life. So I was hopin I wouldn't have to go there.

As for the RCA's, I unplugged them from the unit and put my ipod through them and it was fine. Also ran them straight back between the seats and the stereo still had the whine.

Would one of these grounding kits I hear about have any effect??

[dephrag]

Ok, now I feel really dumb.. just before I posted this I searched for someone who had the same prob.. I didn't think it would fix mine so I posted anyways.. Well on my next trip the the car I try adjusting the levels on my amp.....the gain in peticular (which was maxed), put it back to normal and guess what! I just realized I wasted about 5 hours of my life.. Thanks guys..

[PoorManQ45]

Ok, now I feel really dumb.. just before I posted this I searched for someone who had the same prob.. I didn't think it would fix mine so I posted anyways.. Well on my next trip the the car I try adjusting the levels on my amp.....the gain in peticular (which was maxed), put it back to normal and guess what! I just realized I wasted about 5 hours of my life.. Thanks guys..

LMAO, you read my post!



Glad that I could be of assistance.

Setting the gain too high actually causes the noise floor to be raised quite a bit. I mean, the whine that was there, is still there, but by turning the gain down you lowered the amplitude of it.