BIG alternator whine after new amp!! :(

[Heeltoeclutch 10+ year member]

Guys I'm really hoping you can help me...

I just finished installing a Zed-built Crunch CR150 from the 90s in my car for my front (stock right now) speakers. During the install I turned the car to Accessory to test them, and they sounded great. However, when I went to turn the car on to leave my friend's garage, OH HELLO huge alternator whine from the fronts! It gets louder the higher the gain on the amp is but even with it down all the way it is FAR from acceptable. Its pitch directly correlates with engine RPM.

I have

-Pioneer AVH-P4300DVD

-Knu RCAs (shielded I think)

-Knu 4 gauge power wire and ground

-Knu/Scosche speaker wire

I wired to each door and then tapped into the stock wiring there. Did not have time to try and go through the boot last night.

I am stumped though. I've read through the stickied thread on ground loops and such before. I rechecked everything; I grounded the amp to a bolt that goes into the chassis (I did not sand to remove paint though-that alone couldn't cause it could it?). My power wire is routed along the passenger-side doorsill, RCAs along the transmission tunnel. I think that's far enough apart. However there is a BIG bunch of RCA cable coiled up on the left of the amp, as the RCAs that came with Knu kit were much longer than necessary. I read to coil excess by the amp instead of by the HU because there are more power wires and stuff back there.

I am pretty **** sure I didn't hot-swap any RCAs, but they did sit on the carpet plugged into the HU but not to anything else for a short time while the car was on. Could that have done it...?

I'm really frustrated guys. If you can help me I will be eternally grateful and give you massages and bake you cookies. What I'm really afraid of is that the amp itself is causing this... is this likely?

Clifs:

-Amp Ground issue?

-Noise induced in RCAs?

-Pico fuse-don't think it's blown... but could it be?

-Amp itself causing it...?

Thanks so much guys. I mean it about the cookies. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

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[bubbagumper6 5,000+ posts]

Why didn't you sand the paint off the chassis when you grounded the amp? That was really stupid considering it would have only taken 10 seconds to do it then and it's going to take you a lot longer to go back and fix it now.

 

[CHEMMINS 10+ year member]

How to Ground your H/U's rca's *pics* - Realm of Excursion

This^^^

 

[Heeltoeclutch 10+ year member]

Why didn't you sand the paint off the chassis when you grounded the amp? That was really stupid considering it would have only taken 10 seconds to do it then and it's going to take you a lot longer to go back and fix it now.

Cuz i had a gf and her friend waiting to be driven home and was trying to do things quickly - it just slipped my mind. Do you think this alone could cause it?

And about grounding the RCAs - if the pico fuse is blow, would it make noise even when the engine isnt on?

 

[CHEMMINS 10+ year member]

If the alternator is not spinning....how can it introduce noise?

 

[Heeltoeclutch 10+ year member]

I wasn't sure if pico fuse noise was alternator-ish whine or noise of some other sort - never heard it before.

Can someone please explain why not sanding the paint away would produce alternator whine? I will gladly go back and do it I just want to understand why it would cause it.

 

[CHEMMINS 10+ year member]

It won't affect alt whine.....but it does affect your current. You have the potential to starve your amp. And I never chassis ground. Always back to the batt.

 

[Heeltoeclutch 10+ year member]

It won't affect alt whine.....but it does affect your current. You have the potential to starve your amp. And I never chassis ground. Always back to the batt.

Alright. I was considering this last night on the way back home; if I do ground back to the battery could that remedy the whine? i.e. do you think it is the ground that is causing it?

I don't know much about this, other than reading the stickied thread on ground loops and such.

 

[Trancer 10+ year member]

Go back to your ground and sand it down for a better connection. If you dont sand it down, the paint between the wire terminal and the chassis is not making a good connection. Its not just the bolt and nut that you are trying to get a good connection, its the wire terminal and the floor of your vehicle that makes up the other half of the connection. If that doesn't fix it, then run a separate ground on the other side of your vehicle. I had the same problem. I was running a 1/0 awg cable to ground my amps and I was having a huge alternator whine. It was bad. I ran an additional 4 guage wire to the separate side of my truck and it fixed it.

 

[Shinju 10+ year member]

Did you get the amp used from someone here?

 

[-01limited- 10+ year member]

I'd check the pico fuse first and grounding your rca's at the headunit.

 

[dragnix 5,000+ posts]

check continuity of your RCA preouts on the unit

 

[Heeltoeclutch 10+ year member]

Alright guys sorry I didn't update sooner; what all happened was after I put the seat back in one of the RCAs must have become un-ziptied (cheap ties that with the knu kit) and was sticking up.. I moved the seat back and forth to test for interference and everything felt fine. As I drove away I noticed that the driver's side door was not making any sound. //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif I checked everything yesterday and learned that the left channel had been ripped from its plug thanks to the crappy ziptie coming undone! This must have blown the pico fuse, as I grounded the RCAs at the HU, replaced them with some others I had lying around, and now everything sounds amazing //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Thanks for your help guys. If you're in MI stop on by for cookies //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif