Intermittent alternator whine problem!! How to troubleshoot?

[PittViper 10+ year member]

I have usually no engine whine, and that is great because I hate it. But every once in a while it will show up! When I start the car cold, there is no noise.Then maybe, but not necessarily, it will happen and stay that way, or it might not. Can't predict it at all.

Sometimes I'll turn the hu off, then back on, and it goes away, but sometimes not.

Car: 2008 Chevy Aveo5 4 cyl, factory alternator.

Equipment:

Alpine 7996 hu

Components: Polk db6501 shallow mount.

Component amp: Rockford Fosgate P400-4

Subwoofer: Alpine 12" type R

Subwoofer amp: Rockford Fosgate Prime 750 monoblock

Enclosure: R/T 300

Wiring 4 guage, combination of Rockford, and Pyle.

Ground and Power distribution blocks (power is fused)

I had this problem when I was only using the 4 channel amp bridged to run the entire system.

Recently added sub amp, problem still there.

I don't think it is how I have the amps mounted, because for a long time I had only one amp.

What gets me is that it is intermittent, therefore very difficult to isolate and fix.

Please offer me some help, I'm sure there are those here that have seen such a problem before.

Thanks,

Viper

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[Marauderrt10]

Do you have your RCAs routed anywhere near the power wire? That will cause the alternator wine

 

[maylar 10+ year member]

You have a bad ground. Check the ground wire at your component amp and clean the connection between the wire and the vehicle. 90% of the time that's the problem. Also remove all RCA cables from the amp and give them a good twist when you reconnect them to be sure the RCA shells scrape the connectors clean. If you still have problems after that, check the ground wire on the HU.