Read inside... fluxuating current....., Explaination? Options

[Mstoochn]

my 5s started to put itself into "start only when it wants to mode" so i checked my grounds, alt and battery...
battery is fine, altima redtop 14.1volts, grounds are fine (big 3, trans, starter)
but then... i started it up and checked my alt at idle (its a 110amp bosch alt, yes im using a 120amp fuse not the stock 100)
at idle im charging at 13.8 volts, then i bought the car up to about 2500-3000 rpm just as the turbo starts to spool and the volt reading goes nuts.... its fluxuating between 9 and 14 volts. i also notice when i hit the GAS (not brake) with my lights on they dim... what the ****?! (interior and headlights)

all my logic about automotive charging systems has gone out the window...

when ur alt is running as a higher rpm... it makes more stable HIGHER current?.... should it not...
its almost as if the alt is failing as it increases speed

this is my second alt in a month.

This post has been edited by Mstoochn: Dec 5, 2009 - 4:41 AM

[Bitter]

theres a wire that feeds power to the alt, not sure what it is on this model but iirc on the camry it was white or green. if that wire is making a bad connection...

check the connections and terminals and connectors. we had a taurus in with intermittent battery light etc like you have and she was sure she needed an alt. turned out to be a loose/burned connector at the alt. repinned it and voila, no problems.

[Davinci]

dead diode on rectifier pack. if you have a scope, check ripple curent. it should be way off.