Pioneer HU: buzzing only when faceplate is off

[adam71 5,000+ posts]

When I started installing HU's(1981) there were no amp out trigger, just ant turn on.When amps started to become common place, a relay would be needed because the in HU relay would smoke easy. These days there making higher current amp turnOns and todays amps require very little draw to turn on. But you being a little green, I would not expect you to know much about car audio history.//content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

Heyyyy, be nice. That is something that I didn't know though. BTW, I'm not green. I'm just not that old. //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

 

[nobb 10+ year member]

Thanks for the suggestions, but I fixed the problem. Turns out I was a cheapass and used spare rca's (the shitty ones that come with your dvd player) that I manually extended with ethernet cable and solder. I was getting ~1ohm resistance between the grounds from one end to the other. I spent an hour and bought proper rca connectors which I crimped onto standard tv coax cable. No more ground loop. Btw...my amp's signal wire is not connected to the HU...instead its connected to the accessory wire for simplicity (because I have a carpc that relies on the acc wire too)