Engine bay noise after HU install...
 

Hey guys, just installed a Pioneer AVH-P4400BH touch screen receiver and everything seems to be working okay. However, now whenever the car is on or in acc I'm getting a high-pitch whining noise from the engine bay. Did a search and couldn't find anything. Any ideas before I go back and re-do everything? Any help would be greatly appreciated. Thanks.

I had a feeling it was going to be a Pioneer head unit before I opened your thread.

I sold car audio equipment a couple years ago, and I remember hearing from the installers that for whatever reason the Pioneer head units would sometimes cause alternator whine.

I did a quick search and found these links.

http://www.diymobileaudio.com/forum/...tor-whine.html

http://www.caraudio.com/forums/wirin...whine-fix.html

I had a tC that would do this when I had a device plugged into AUX. I always thought it was a bad ground.

Thanks for the links! Will try it later in the week when I get some time, sounds like it won't really damage anything to run like this until then.

Any updates on this?

I've got a similar issue but only after my AMP install to factory head unit using level inputs from the head unit.

If your rca cords are not shielded and you ran them next to the power wire you will get the whine through the amp. Also make sure you have a good ground on the amp and don't wire the ground on the amp to the ground on the battery. Ground it to bare metal.

I ran my RCA cables in the middle so not next to power.

One thing i can think of is that I ran my ground wire to the rear ground point just near the boot lock.

There was an existing bolt there and had other things connected.

You more than likely have a poor ground causing a ground loop, or in the case of an amp, it poorly grounded or bad rcas.

The whole pico fuse thing is kinda BS Ive brought it up on DIYMA many times, people complain its gets blown when its doing its job. It blows from hotplugging rcas, which you arent supposed to do. OP did not state he was using an amp, so even if he had the pico fuse problem he wouldnt know it using the internal amp.

@AL008 what amp do you have, and do you have any pics of your amp grounding? If your amp ground is loose, dirty or poorly crimped you can have that issue. Also, is yours a whine or static? if you exp static with 0 volume, then you have too high gain set or an amp with dirty power.

How do u get clean rather than dirty power? I get static not when vol is at 0 but rather when I pause it

Just quality of the powersupply in the amp, as well as amount of gain being used.

Why not ground the RCA's?

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I want to verify two things before we go any farther.

1) It happens with the engine on and also with the car on ACC with the engine off.
2) The noise is coming from under the hood, not through the speakers.

Does not happen with everything off. Does happen with engine off and in ACC. Sound does come from under hood, NOT from speakers. Tried the wire around the RCA's on the back of the head unit, did not help.

If the engine is not running, we aren't talking alternator whine, obviously.
If you pop the hood while in a quiet area, can you localize where it's coming from?
I've heard whining noises from under the hood but only when the engine was running.
So far this one beats the hell out of me.