alternator whining

[skinz]

i fitted a new alternator about 10 months ago and its started whining already, i think is cause of my sub putting 2 much strain on it, im gonna take it bk under the warranty but was thinking im sure that i have a 90amp alternator, would i be bet of fitting a 120amp, can i fit a 120amp on my car (AEB)

 

[aragorn]

Presumably it wasnt actually new, it was a refurb and its probably been built with crappy parts.

I doubt its anything to do with your sounds, unless you sit parked up trying to blow the doors and windscreen out you'll never draw anywhere near 90A.

 

[skinz]

Blow my windows out..... Erm well.... I am a bit of a basshead lol, 4000w sub 1200w 6x9 then my door speakers

 

[aragorn]

Thing is, its not actually 4000w.

Assuming that rating is even correct, which i very much doubt as a real 4000w amplifier would cost thousands, the maximum RMS power displayed by a car amplifier is usually only achievable for very short periods of time, and the average power is waay below this.

 

[Oranoco]

Yep. I run an 1800w monoblock amplifier but by time you've applied all the maths to it it's actually 550w RMS. Is the whine coming from the alternator or through the speakers like interference. If it's whine through the speakers check and clean up the earth on the rocker cover as mine worked loose and kept giving me a whine above 2krpm

 

[skinz]

my m8 is breaking his audi so robbed his alternator 4 now, took mine off and it is the bearings so gonna take it bk 2moro