Help with head unit install

[Bladerunner]

Hi guys, have just hooked up a new head unit to the existing speaker loom and everything is sweet..... as long as the ignition key is in the 'acc' position. As soon as I turn it to 'on', i get a loud whine from the speakers that doesn't go away no matter what function I have the head unit set to.

Any suggestions?

 

[Guest]

Sounds like alternator whine... Double check your earth and power connections, it's easiest to just use the ones from the standard stereo wiring. Also, have a quick read of these:

http://www.termpro.com/articles/noise.html
http://www.crutchfield.com/S-YdFnFse7pXV/tech/kb348.html
http://www.caraudiohelp.com/newsletter/alternator_whine.htm

I ended up earthing mine on the metal frame of the centre console, haven't had any problems what-so-ever. Good luck!

 

[Bladerunner]

The whine does not change in pitch according to rpm; the engine doesn't even have to be running. This only happens when the ignition system is switched from 'acc' to 'on'.

I know my battery is pretty rooted; i may swap it out to see if this helps.

 

[Bladerunner]

Battery makes no difference. The whine DOES get louder when I remove the earth and gets quieter when I earth to the metal frame inside the dash. It is still very noticable however and is far from tolerable.

Could it be the +12v supply? I am using the standard stereo one, any ideas as to where else I could source it?

 

[Hipsi]

a number of places. Grab a test light and start prodding wires. try taking it from the cigarette lighter?

 

[Bladerunner]

Also noticed that i get a 'thump' when turning off the acc and taking the key out; related?

 

[Guest]

first of all what head unit??

my first guess would be
crappy earth(s)
somethings creating a ground loop,

NEVER use the factory earth for a aftermarket stereo, its poor at best,
direct chassis earth is best, factory power is fine.

what other accessories have you got in the car that arnt standard?

 

[Bladerunner]

Nothing else.

But its official; im not going to mess with this any more. When testing alternative power sources, I got a spark and heard a click. Now the white lights on my hi-vis dash don't come on any more (the actual red indicators still light up, but the dials don't glow white).

Car is going to an auto electrician, i hope i didnt do anything too expensive.

 

[Bladerunner]

Well ive blown the interior light fuse, hope i haven't damaged anything.

 

[Bladerunner]

Just fyi; there is only the head unit being installed, so an earth loop is out of the question.

I tried several different earth points; all were clean and only helped marginally.

 

[pu-11-me]

G'day Andrew,

Are you sure these speakers aren't amplified? This is a common problem with amplified speakers because unsheilded RCA cables can pick up a whining noise from anything with current that runs near them....

The other possibility (and i'm clutching at straws perhaps) is that your connections are not not insulated properly (soldered connections with electrical tape insulation is the way to go), causing interferance with another powered unit close to it such as ciggie lighter, A/C, screen etc.....

Hope you work out whats going on and get it fixed

Dawso

 

[Bladerunner]

I am reasonably certain that the speakers are stock and passive. As for the wiring, i soldered and heatshrinked it myself. Maybe thats the problem hahaha...

 

[pu-11-me]

Lol..... Nah that all sounds OK, but i would as a precaution just run electrical tape over the connections and see if it makes a difference, heat shrink will shield it for cureent but no so much for interferance....

See how you go

Dawso

 

[Bladerunner]

Well after replacing a fried fuse, everything is back to normal! I've purchased one of these noise filters:

http://jaycar.com.au/productView.as...&pageNumber=&priceMin=&priceMax=&SUBCATID=563

and placed it on the +12v input from the standard loom. i am happy to say that the whine is almost completely gone

Now the wiring is all bundled up and tidy, time to get onto the carpc install.

 

[pu-11-me]

Nice to hear its fixed!

Dawso

 

[Bladerunner]

Another fright today; power cable for the pc was tripping fuses. Turns out it was the jaycar plug not my soldering/installation. One of the tabs had simply snapped while I was screwing the surround on. Glad I found that fast before something else got fried.

Bad news is I can't do any more until I get some more fuses; while i feel uncomfortable relying on them to find my errors, can't think of a better way currently as most of the testing is done when everything is already taped up/insulated.