Alternator whine through stereo - 304

[savage1987]

Car is a VN 304, the noise is much more noticeable when I turn on my headlights. Comes through the amped front speakers.

Also, because my fuel pump is a fairly noisy Walbro GSS341, I can hear it running if the ski port to the boot is open, and I noticed tonight that at idle the pump sound changes - its RPM seems to drop a little. I've been having trouble chasing a ping as well, which to me screams low fuel pressure (greenfoam tune so that's solid), so I'm starting to wonder if these things all point to a common fault?


Alternator failing, is that a possibility?

You guys no doubt know a lot more about these things than I do so I thought I'd ask!!


Sam

[showbags]

Replace
Battery terminals and earth cables

[savage1987]

Terminals are pretty new, I don't think they are the issue.
Earth cables.. well I earthed the absolute crap out of the amp, and the block has an extra earth on top of the one it had from factory.. so I'm not sure what further to do there.

[HoldenCommodoreVE]

Could be worth looking for a more powerful alt at least you know that your fuel pump has got plenty of volts going to it at all times.

[HoldenCommodoreVE]

Pings can be caused by timing aswell.
I believe if it's to advanced it will ping I could be wrong though

[VK SL 3800]

Check what the battery volts is at idle and flight, should be about 14v and can be a little lower at idle but still above 12v, chances are the volts are dropping at idle so your pump slows a little which is normal. Could cause a ping if the volts drop critically low but you would have more problems if that was the case.

When you hit the lights your alternator starts working harder so your volts will drop a little and you will hear it whine more, when they whine through the stereo its because one of the little electric dampeners anti-static things (there real name escapes me, looks like a little capacitor with one wire going to it usually) is playing up and you get a buzz. Cheap and easy fix.

[savage1987]

Pings can be caused by timing aswell.
I believe if it's to advanced it will ping I could be wrong though

Yep, but what I was more saying is that the timing is spot on - greenfoam tunes have always been excellent in that regard - so I must start looking at other possibilities

Check what the battery volts is at idle and flight, should be about 14v and can be a little lower at idle but still above 12v, chances are the volts are dropping at idle so your pump slows a little which is normal. Could cause a ping if the volts drop critically low but you would have more problems if that was the case.

When you hit the lights your alternator starts working harder so your volts will drop a little and you will hear it whine more, when they whine through the stereo its because one of the little electric dampeners anti-static things (there real name escapes me, looks like a little capacitor with one wire going to it usually) is playing up and you get a buzz. Cheap and easy fix.

The capacitor thingo - is that on the amp, alternator, where?

I'll check the volts running @ idle, and running @ ~2000rpm, and see what it looks like (terminals have built in V- meter --- easy job!)

[KAL SPL]

Ten characters

[VK SL 3800]

The capacitor thingo - is that on the amp, alternator, where?

Back of the alternator, im not sure but the early girls have them on the coil as well so just check there too.

[drewVHSS]

Check what the battery volts is at idle and flight, should be about 14v and can be a little lower at idle but still above 12v, chances are the volts are dropping at idle so your pump slows a little which is normal. Could cause a ping if the volts drop critically low but you would have more problems if that was the case.

When you hit the lights your alternator starts working harder so your volts will drop a little and you will hear it whine more, when they whine through the stereo its because one of the little electric dampeners anti-static things (there real name escapes me, looks like a little capacitor with one wire going to it usually) is playing up and you get a buzz. Cheap and easy fix.

Check the "Condensor" on the back of the alternator to make sure the thin wire hasn't gone brittle and broken off.
There should also be another noise suppressing condensor on your ignition coil.
If these are faulty you would experience your electrical noise issues.

[savage1987]

I hate that Holden decided to put the coil there..... all the wiring I can see seems OK.. but that's not much of it. Same on the alternator - the main power wire is secure, and the injector-style plug is secure as well. Not sure if there's meant to be anything else attached but there doesn't seem to be.