I have a very faint alternator noise. you can only hear it at the lowest volumes, and its only evident around 2500-3500 RPM. the grounds are solid, i used high quality cables on both amps.

is there something / a product, i can attach to the alternator itself that will help me with this?

 

There used to noise suppressors, make sure to get one rated for the output of your alternator.

Just asking, are the amps wired direct to battery ?
Have you tried changing the ground location ?

 

Thanks Scrambler,
the grounds are very short on the amps, just a few inches (3-4"?), very heavy gauge wire. When we installed the amps, behind the drivers side jumpseat, we ground off the paint to bare metal on the floor, when we attached the grounds to the bolts that hold down the jumpseat frame directly to the cab floor itself.

the amp power goes directly to the battery.

I recall when we discovered the noise, behind the headunit he put a wire with a big chunk of something on it 'in-line' with another wire and buried it behind the dash, that filter took care of about 90% of the noise. I suppose its attached to one of the RCA's, or something?

we did the job together months ago, and it had been a long night doing all the work. and im just being picky at this point but id like to see if i could suppress all of the noise completely.

he mentioned the alternator could be going bad and is just noisy.

=====
component list:

Rainbow SLC 230 5 1/4 component set up front (passive)
Kenwood rears
Kicker 10" sub
Kenwood KDC-X995
Zapco ST1 for the sub
Kenwood X600F 4 channel

 

i talked to a friend briefly today, he said to install a capacitor between the alternator and the battery. but i have no idea how to do this...

 

Chk out some HAM Stores, Amateur Radio that is !

 

I can source the parts, I just have no idea what parts to buy or how to install them properly.

 

Most have directions.

Some have schematics on the device.

Source out the part you want for the alternator based on the output; these filters used to be marked with either "in and out" or "+.and -.

The filter that go on the power line to the component are usually reb blk, red - in and blk - out.

 

So I just need to walk into a place like radio shack and ask for a line filter for a alternator?
I have no idea what the specs are on our alternators...

Sorry, I've never had to deal w something like this before.

 

Rat Shaq, No but maybe a Ham Radio Outlet !
You will need to know what your alternator has for output, I am sorry but I have no idea what that is.
Find out, give yourself a safety and future expansion margin of 25%, then, buy.
Me, I would get a 150 Amp unit minimum and it may be that you will only,find values like 100/150/200 Amps anyway.

Let me look around.
Ltr

 

Interesting read !

http://www.termpro.com/asp/pubs.asp?ID=121

Found it in my searching.

Also, finding not many companies make in-line alternator filters, plus $$$.
You/your friend need to do some chkg and locate where the noise is getting in the system; once determined then block it at that point.
Might be cheaper and easier than locating and installing an alternator filter/cap.

Sorry that is not much help but what I've read is every system is different but at the same time they have similar fixes and one is alt whine and nobody puts on an alternator cap/filter in-line or otherwise, they all appear to fight it at the entry point.

I have asked three companies about their DC Alternator Filters, waiting to hear from them and will post.

Again sorry and try to determine the noise is getting in.

 

i'll have to take a closer look, they might be sharing the same power wire, while its heavy professional grade wire, that still might not be idea. they have very short 3-4" independent ground wires but are grounded to the same location; bolt for the side jumpseat into the body floor.

i know when we did the install, i watched him swap several different types of RCA cables with no luck.

my gut tells me the alternator is noisy. sometimes i can hardly hear it or not at all, other times i feel like if the battery is getting a charge after long sits, or if its a moist / foggy day out, i can hear the noise, especially at higher RPMs and low volume levels.

 

If the noise increases with wet weather, to me that indicates bad connections.

Try some of the chk test suggested I that write up.
Maybe you can determine where and when.

Ltr

 

i heard it tonight, the sound does not vary with the volume of the of the HU. it stays the same. its covered up by a very low volume level. its most apparent around 2750 + RPM

that was a good link, i'll take a look at some of the connections, and if the amps share any.... I know its not the RCA's since i saw them get swapped.
oddly enough the guy that did my stereo was able to eliminate the noise by wiring the amp so it sent all its power to 2 ch instead of 4, but i didnt want it configured that way so we put it back.

id like to try the filter idea. its really not enough noise to make me drive out of my way back to his shop 2 hours and trouble him. im hoping i can nail it down on my own.

 

Another thing to consider is contact an supplier like Sonic, I like them, and ask about noise suppression.

I will look around a little more...

 

Got feedback from Sonic Electroixs... :

Here is the addie for a filter: http://www.powerwerx.com/emergency-v...r-150-amp.html

Here is some of the e-mail:

Grev,

Unfortunately, the strongest noise filter we carry is rated up to 40A,
not 150A.

P.I.E. NF-40 40 AMP In-Line Power Lead Noise Filter:

http://www.sonicelectronix.com/item_....E.-NF-40.html

However a little research turned up this Newmar 150-A Alternator Line
Noise Filter:

http://www.powerwerx.com/emergency-v...r-150-amp.html

Good luck!

Sincerely,


Raul C.
Customer Commitment Team
Technical Support
Sonic Electronix, Inc.

Toll-Free: 1-877-289-7664 x 2493
Direct: 1-661-670-2493

 

If the noise is mainly at higher rpm's , i would suspect brush float in the alternator.
The brush springs are probably getting weak and not keeping the brushes tight enough to the rotor .The excess arcing will induce noise in the system.
Takeda had a write-up on replacing the brushes with pics and the NAPA part number for the brushes.

 

Scrambler i really appreciate those links, i think im going to try and find that Newmar, thank you for going through all that. you got me on a start with those products...

OTR, i'll try see if i can search for that write up and weigh my options. its def only apparent during that RPM range, and it doesnt change with the volume of the HU at all, the lowest levels of music cover it up... but my ears are keyed into listening for it, which makes it worse. :)

 

No problem, the price $$$ will get ya but if you are putting big money in the tunes then it may work out.

What OTR says makes sense and changing the brushes shouldn’t be too hard just time.
Also, if the alternator is OLD, consider changing it out for new and some alternators have noise suppression.

 

Thanks guys, really appreciate the help here with this...
the alternator is OE, 60,000 miles on the truck... its still under warranty, which makes me lean towards adding the filter inline so if something happens over the next 40k on the rollers, ford doesnt point fingers at me doing work on the alternator myself.

thread reference, brush rebuild from Takeda
looks very easy, you dont even have to pull the alternator.
https://www.ranger-forums.com/showth...rnator+brushes