3 replies to this topic

[jam2005]

if i play song in my car i hear a wierd wispering kind ov noise. this changes as the revs change. it alters wiv the engine. y? my mate says u can buy a device to stop this. but wots the device and where can i get hold ov it? also y does my battery run flat wen im listenin 2 musik. it does this even wen the engine is runnin do i need a dry cell deep cycle battery? plz help jam2004

[Guess-Works.com]

sounds like your alternator is struggling.... while your engine is running, the alternator provides the power to run all the electrics, and re-charge the battery after the intial current soak used by the starter motor... If the alternator is defective or does not have enough power to run the electics then the additional power supply is provided by the battery... hence eventually the battery will go flat.

As for the device, it's called a choke, and is bassically a whopping capacitor which is fitted either in the power line to the unit, and/or across the alternator this suppresses the 'buzz' noise which is introduced by engine ( sparks ).

[philster]

Its probably as guessworks said (sorry mate don't know you're name!) a problem with the alternator, some do have a built in suppressor which reduces 'alternator whine' and this is probably not working properly hence the reason you are getting a noise.
As for the battery going flat you shouldn't need a drycell battery just a good lead acid one (as in normal car battery). You can put a higher ampage battery in (just get the one with the highest cranking amps you can that'll fit in the battery tray) Also if you're changing the alternator put a 55amp or higher in which will help keep the battery in tip top condition.
If you do change the alternator and battery for more powerful ones its a good idea to check all you're power cables and earths are in good condition and beefy enough to take the xtra ampage.
I did this to mine a few years ago and i can run the PS2, tft screen, stereo and interior light together for hours without any problems.

[malletts mallett]

If it's an alternator whine 99% of the time it's a bad earth on a item in the signal path.

It has nothing to do with you battery,drycell or otherwise.And nothing to do with the popular myth or RCA/Power cables in proximity. I'd suggest you re earth your headunit seperate from the ign loom and rearth you amps if any.