Update2: Probably no more help needed just yet

Hey guys,

So I've had these two issues plaguing me for probably the past 7-9 months, several attempts to fix and it's just doing my head in. First issue is that I keep getting a lot of belt noise (very very loud screaming sound, not just a small squeak) from my AC belt. This was caused initially since I replaced the AC belt - after that, whenever I started the car up and turned the AC on, it'd have an extremely loud screeching sound and wouldn't stop until I turned the AC off. I tightened that belt up a fair bit after advice from a few mates, but a new issue rose: The same sound will happen now even with the AC off (so I'll just turn the car on and BAM). It'll either last maybe 5-10 seconds and go away, or just stay forever until I turn the car off, and start it up again (then it goes away). It'll also occasionally give me a 1-3 second squeal while driving with the air con on (rarely)

Not sure what to do, I can't just keep tightening the belt.. and surely it's not just the belt itself, it does work properly.. just something seems to go wrong randomly.

Other issue is speaker (engine noise/alternator noise) whine coming through my front tweeters only. I've tried several times to remove it, such as swapping out the amp, relocating the ground, ran complete new wiring for everything. No idea what to do - I've read that theres noise suppressors that you can buy, haven't really read into them.. I feel like that's a "half-assed" solution however. The car didn't have this whine when I first got it, it only happened around the time I had a new headunit installed and re-did the sound system myself. Where can I look for the source of the whine??

Wall of text but I'm coming to my wits end - I'm sick of getting in the car, to be embarassed having it squeal it's head off in my street (luckily hasn't happened at the shops yet!), not being able to use the AC scared that it'll scream like a pig mid-traffic and when that isn't giving me trouble, having my driving experience ruined by this stupid whining sound from the speakers..
Thanks in advance guys, would really appreciate any direction here!

 

dasic1
Take the belt of the AC and turn it over by hand. I had to get mine rebuilt as the bearings had failed. But it always squealed when the AC was on

Take the belt off to check both the AC idler, and AC drive pulley bearings.
To check the compressor bearings reach in and turn the inside part of the AC pulley (because the AC clutch will be disengaged).
 
Also a silly question: Could the squeal be from the alternator instead? - a common problem.

does the car have an aftermarket amplifier or stereo?

if so, the wiring can get noise from the ecu and ignition system. Mine whines a bit as rpms increase.

as for belt squeal. do as redtarga said. Also note that if the belt has slipped for a long time it can actually burn out and glaze over causing it to slip more.

Check your tensioners are done up tight and that the belt is tensioned very firmly.

If you continue to have issues, message Scope and see if he can have a look at it. he is very good at what he does. 

Cheers, 

-Eric

I'd suggest 90* is good, it's always what I gauge mine on.

Pullies might also have some glazing.

Reddtarga
"How am I checking the AC idler and drive pulley bearings? What do I do to check their condition?"
Shot bearings may feel stiff or rough to turn.
Have you driven the car with the A/C belt off to see if the squeal happens?
 
"Did you mean regarding the alternator belt making a squeal, or as in the alternator is causing that speaker whining I mentioned? I don't think it's the alternator belt, considering the squeal used to only happen IF the AC was on.. now it's random."
I meant checking the alternator belt tension?
They often squeal on start up if they are loose.
 
Re whine in speakers
 http://www.termpro.com/asp/pubs.asp?ID=121
Must be covered in there somewhere
 

Haven't tried with the belt off, I'll give that a go. It'll just be hard to try as it happens occasionally, so it'll be hard to tell if it's not making it sound due to the belt being off (thereby fixing the issue) or I just haven't been "unlucky" enough for it to happen

I'll check the alternator belt tension as well, didn't think of that!

Thank you for the link regarding the audio system. I've tried several "guides" and all of them always end up referring to buying a noise filter. This one seems to be well written and actually useful so I'll be sure to give this a good read, thank you heaps

Never got a second opinion after posting video. Bumping so maybe someone can see it

Did some further researching, and I believe possibly one of my diodes may be faulty in the alternator - I'll try and get my hands on a multimeter soon (may have to buy one) to figure it out. Not sure if I'm testing it the right way, but I'll be testing for AC voltage at the battery. I'm assuming that if I get any one of the diodes must be on it's way out.

Can anyone confirm if thats the way to go?

A good auto electrician can confirm if something is wrong with your alternator. They can rebuild it if it's a genuine denso.
Other than an autoelectrician, best advice don't play with it.