Alternator whine in speakers

[JNickolas]

88 325ix no fader

pioneer deh 9300bt hu

2 Infinity 475a amps

2 infinity 61/2" 62.9i coax rear 2ohm

2 infinity 51/4" 5030c components 2ohm front

1 kicker SB L5 10" sub 4 ohm trunk

the cab speakers are going to 1 amp. the sub is going to the other. sub wired in series @ 4ohms bridged. I realize its not the correct amp to use for the sub, but got a package deal.

4awg power to a dist. block then 8awg to the amps.

8awg grounds to the paint free stud that the battery ground connects to.

All new 16awg to the cab seakers and 12awg to the sub.

3 sets of rca's to the amps.

I am getting crazy interference through the speakers when the car is running. With the key set to acc. it sounds amazing. the whining increases with rpms.

heres the kicker, whining goes away when i unplug front or rear rca AND touch it to a bare spot (door hinge).


The only thing i can think of is....i ran ALL the wires on the passenger side too close to the 12v supply. Or theres a break in an rca wire.

i tried moving the grounds...no change.

do you think its a ground problem in the engine bay?

Any thoughts??

thanks!

[LittleEcker]

The only thing that I've heard in reference to this subject is that the whine signifies that your alternator is going out. I had a whine in mine, and when I changed out my alternator, it went away. Low and behold, it was back in an hour, so who knows what causes it! I'm just as curious as you! Good luck finding it!

[JNickolas]

[ATTACH]76974[/ATTACH]

[matthugie]

It's a ground problem somewhere, most likely behind the deck or at the amp.

[JNickolas]

I think its ground too, I'm going to do impedance tests today. I'm also going to run new RCA's (on driver side), the ones I used were used from my H.S. days.

I grounded to the spot behind the battery first, then moved over to the factory jack mount (wire brushed paint), then back to the stud.

I've seen post and videos of people with pioneer h.units having the same problem. Their solutions are to wrap a copper wire around the rca outs at the h.u and keep it in contact with the casing of the HU... I think this tells me the HU is not grounded properly. Looks like theres a good ground location above the brake peddle.

I'm also going to sell the 61/2's (if anyones interested they are brand new) and put the stock size back in the rear deck. The components w/ separate tweeters are noticeably better. Plus I cant argue the factory look.

While I'm doing the impedance testing, I'm going to check power to the amps to see if a capacitor is necessary to keep proper power supplied.

Any input on how to size the capacitor?

[StereoInstaller1]

Don't spend a whole bunch of time diagnosing, it is likely a bad deck.

Do you get a weird "screedling" noise between tracks on a CD? If so, its your deck.

Here is a quick way to tell: grab an ipod or whatever, get an 3.5mm to RCA adapter cable.

Unplug the RCAs at the amp, plug in ipod.

Start car, turn on stereo, make sure music is playing.

If there is no noise, its your deck.

Pioneer of that era were notorious for noise issues

[AndrewBird]

In my e34, I had the RCA's running with the amp power cable for about 3ft and that was enough to cause alternator whine. Moved the RCA's to a different area and problem solved.

[lwde30]

Don't spend a whole bunch of time diagnosing, it is likely a bad deck.

Do you get a weird "screedling" noise between tracks on a CD? If so, its your deck.

Here is a quick way to tell: grab an ipod or whatever, get an 3.5mm to RCA adapter cable.

Unplug the RCAs at the amp, plug in ipod.

Start car, turn on stereo, make sure music is playing.

If there is no noise, its your deck.

Pioneer of that era were notorious for noise issues

im having the same problem.... but couldnt it also be the rca cables coming from the deck