alt whine, ground issue?

Ok I have a 94 jeep grand cherokee and a whole aftermarket system installed. The problem I am having is while the truck is running there is alt whine (can tell it varies with speed). But if I pull the e-brake handle the whine goes away (likely it kills the feed to the daytime running lights and it goes away). What would be causing this a bad ground at the stereo or something else not sure. All amps are grounded properly in the rear of the truck right to the metal body(scraped paint away when i mounted them). Should I ground the deck somewhere else? (run a long ground lead to different part of the dash or what. It does this no matter what input I am on (cd, cd changer, aux, radio, ipod.

unplug the RCAs from the amps...one at a time. If the problem persists is the amp. If the whine goes away, then possible head Unit.
Can you give us a model #?
Is it a PIONEER? RCA SHIELD REPAIR

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What kind of HU? Some Pioneer and Panasonic IMO have bad rca grounds
Touch a ground wire to the outside ring of the rcas see if it goes away.if it does its the rcas or HU

Try unmounting the amps from metal *****Not the Ground***** The amps themselves.

I mounted my 4k to metal in my jeep and it made noise. took it off and put a carpet board behind it and the noise was gone

It's not the amps or head unit themselves as I've tried multiple amps and head units and the noise is still there. The amps are mounted to carpeted board under the rear seats. Like I said it only has wine when the daytime running lights are on and goes away completely if you pull the e-brake handle - that shuts off the daytime running lights ie headlights. The radio is a clarion drx9675z, the amps are a rockford power 400.4 and a power 1500.1bd. The speakers have all been changed to rockford 6.5" components front and rear, and new wiring was done from the amps to the speakers as well to the subs with monster cable wire, as well as 2 sets of monster cable 4 channel 401xln rca's. I think the problem has something to do with a ground somewhere in the vehicle that is in a junction ground point in the dash as when i turn on the headlights it gets quieter than with the daytime running lights and completely gone when i pull the e-brake.

There is a good chance that the DRLs are powered via a Pulse Width Modulated power supply.  They sometimes generate noise.  Have you tried turning the gains all the way down to see if the noise goes away?

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Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

The gains on the amps are all the way down they can't go any lower they are down all the way as the HU puts out 4 or 5 volts thru the preouts in the deck. The deck is also preout only no internal amp in it. I've tried to ground the rca's the HU but that does nothing. It seems like an outside source like the headlights or daytime module grounding junction maybe. What else can I try to eliminate the whine other than driving with the e-brake on?...lol

Sounds like a ground loop.  I'd try a few things:

1)  If you haven't done the big three, give that a shot.  At least the grounds for sure.  Check and clean battery terminals.  Check and clean alternator 12v+ terminal. 

2)  Run a wire (~14-16 gauge) from the HU ground to the amp ground. 

3)  Try rerouting the RCAs even if that means putting them next to the power.

4)  Double check all you RCA connections, especially the ones behind the dash. 

Good Luck. 

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You talking to me???

P9 Combo
ID CD1-Pros
Focal Utopia Midbass
10" Brahma
Clarion APX amps

I have done the big 4 already long time ago and i have tried to isolate the rca's before by putting them in tubing all by themselves and they are not near any power whatsoever. Battery terminals are clean and have +/- dist blocks on them and no corrosion from when I did the Big 4 on them. The rca's are taped around their connections as to nothing to touch them and so that they don't come apart. I could try to ground the hu to amp thing but do i ground it to both amps or just the one?

rockyfarted wrote:

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I have done the big 4 already long time ago and i have tried to isolate the rca's before by putting them in tubing all by themselves and they are not near any power whatsoever. Battery terminals are clean and have +/- dist blocks on them and no corrosion from when I did the Big 4 on them. The rca's are taped around their connections as to nothing to touch them and so that they don't come apart. I could try to ground the hu to amp thing but do i ground it to both amps or just the one?

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Running RCAs next to power wire won't induct noise, however if they are run next to something that is part of the light system..... 

I'd suspect the RCAs first, try rerouting them, even if that means putting them next to the power cable (which they won't induct noise from anyway).     

You can ground the HU to the full range amp; the HU will be "grounded" in 2 places: it's current ground and the amp ground. 

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You talking to me???

P9 Combo
ID CD1-Pros
Focal Utopia Midbass
10" Brahma
Clarion APX amps

do you have illumination/dimmer wire hooked up behind the radio?

I had a 87 jeep Cherokee Have the same problem and the way i fixed is to take of the radio out and the post on the back(if it has one) hook the ground right up to the (-) battery terminal. If I am not mistaken the ground is in the harness (that is the way mine was so I used that ground in the harness and did another ground to the (-) terminal from the radio. Try this it might just solve the problem

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Can't be loud then don't have it.

(power acoustik system)
Head unit- TID-896 7" TOUCHSCREEN
ovn1-5500d 09 and another one coming soon
4-12" mofos 12ft3 box to 40hz (wall)
2 batterys, 1 power

vibrationcustum wrote:

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I had a 87 jeep Cherokee Have the same problem and the way i fixed is to take of the radio out and the post on the back(if it has one) hook the ground right up to the (-) battery terminal. If I am not mistaken the ground is in the harness (that is the way mine was so I used that ground in the harness and did another ground to the (-) terminal from the radio. Try this it might just solve the problem

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Your 87 had daytime running lights? 

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You talking to me???

P9 Combo
ID CD1-Pros
Focal Utopia Midbass
10" Brahma
Clarion APX amps