New amp has whining noise

[Bob 50]

I am learning a lot about car audio through my weekend install of an amp in my Son’s 95 Camaro. The head unit is a pioneer dh5000 and we hooked up a 4 channel amp pushing a 12 inch sub and 2 6x9’s. The install went as planned and after finishing all sounded great until we started the car and heard the high pitch whining noise which a believe is the alternator bleeding through. I have tried the following with no change,

Relocated the ground

Relocated the RCA cables coming from the head unit

Relocated the routing of the positive wire

Hooked the neg. wire and pos. wire using different cables directly to the battery

I did hook the amp to a different battery that I set in the trunk and when the car was running there was “no” whining noise.

I would be grateful for any help as I am getting a little frustrated with this project.

Bob

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[gtbike900 10+ year member]

Ground The Rcas Pioneers Are Known For Bad Grounds

 

[Bob 50]

Thanks,

But if it was the RCAs wouldnt the problem still have been heard when I used a different battery that I wired up to the amp which bypassed the charging system for the car?

 

[gunz4me2 10+ year member]

Pioneer decks are known for the PICO fuse issue because when it blows, you will get that whine. Also, ground loops and certain GM vehicles used to be a royal PAIN to resolve.

Unfortunately, if connecting your amplifier to another battery completely isolated from the vehicle solved the problem, you may have noise coming in through the power wire. In SOME cases, a capacitor on the power line can filter out this noise.

ETA: You could have bad diodes in the alternator too. Connect a Digital Multimeter to your battery and test for AC voltage with the vehicle running. If you have more than 1v of AC, you may want to look into replacing/repairing the alternator. IIRC, .5 to .7 volts of AC is acceptable with the vehicle running and any more usually indicates a problem with the alternator.

ETA2: What is the age/condition of the vehicle's battery?

 

[Varinabassing 10+ year member]

i would say try capacitor and see if it helps doesnt have to be very large because your useing as a noise reducer

Oh side note do you pics of the install love camaros and love seeing different ideas in these vehicles

 

[thorshammer1 10+ year member]

Try running the h/u ground directly to the amp. It has killed many an alt whine problem for me in the past.

 

[Bob 50]

Thanks Folks,

I figured I had ruled out about everything except for the power wire carrying the distortion (whine). The battery is fairly new and I had not been having any problems with the alternator.

Is a filter the same as a capacitor in this case?

Bob

 

[gunz4me2 10+ year member]

Those stiffening capacitors that are advertised to keep one's headlights from dimming are quite effective at filtering the AC ripple out of a power line. Sadly, they aren't so good at keeping the headlights from dimming and are NOT a substitute for an inadequate electrical system.

If you don't have a capacitor handy, try thorshammer1's solution and run the ground of your head unit to where the amplifier is grounded.

 

[Bob 50]

Thanks Again,

Tried grounding the head unit to were the amp is grounded and that reduced the whine by 50%. Is there any benefit to running the power to the head unit from the amp?

Wow this is really a pain!!

Bob

 

[integra88 10+ year member]

Stupid question here..Did you run the rca's and the power wire down the same side of the vehicle?? If so, That may be your noise. Just my .02

 

[Bob 50]

Thanks,

They are on the same side but about a foot apart and tried runnung the power wire outside the car (as a test) to the battery with no change.

I have also tried disconnecting the antenna and did notice that when the blower fan is on high it bleeds through.

Interesting to me why none of this bleeds through when I power the amp with a seperate battery?

Also noticed that the distortion does not increase when the volume is increased.

Frustrating!!

 

[thorshammer1 10+ year member]

Thanks Again,
Tried grounding the head unit to were the amp is grounded and that reduced the whine by 50%. Is there any benefit to running the power to the head unit from the amp?

Wow this is really a pain!!

Bob

Excellent! Now try moving the ground to the amp itself. Also re do the ground for the amp making sure it is indeed grounded well.

 

[Bob 50]

Thanks and I will try it (ground to the body of the amp).

I am also going to see were the factory grounds the battery to see if I can improve that. I am also trying to get my hands on a lowner capacitor to see if that does it.

Boy my Son is going to owe me for this!!

 

[thorshammer1 10+ year member]

Thanks and I will try it (ground to the body of the amp).I am also going to see were the factory grounds the battery to see if I can improve that. I am also trying to get my hands on a lowner capacitor to see if that does it.

Boy my Son is going to owe me for this!!

NO Ground to the amps ground terminal.//content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[edzy 10+ year member]

do this to the HU, then plug in the rcas.