alternatory problems

[lord_gufi]

k guys i got a 99 bird, its stock and ive got a system in it, could the stereo be pulling so much from the batt that its draining the batt or do yall think the alt is going out, it whines like a big ol hair dryer literaly, but only after around 2000 rpm can i hear it in the cab, its really anoying me cause my dad just keeps telling me to charge the battery cause my system is pulling it down and i seriously think its my alt, i mean this charge thing didnt start happening till it started whineing, any way please get back tome about this

[rockotman]

If it's whining, it's probably dying...

When one of the diodes goes in the alternator (the most common failure mode), unbalanced currents are the result (the alternator is 3-phase, but when a diode goes out, so does one of the phases) and these cause unbalanced vibration in the stator. The result is the whine that you hear.

If at an idle, you can't keep the voltage above 13V (with extra loads such as the radio and headlights turned off), then it is time to either rebuild or replace the alternator. Do it now, 'cause winter is right around the corner.

[gregmondro]

I had the problem with my alternator. I pulled it out and sure enough, one of the diodes was messed up (supposed to be green, but it was a dark black :( )
anyway, before that I had put in a brand new battery because I thought it was the battery. about a week later, my guages were coming on telling me that the battery was dying. Later that night when I was driving the car down the road, it died (alternator was completely dead by then, and I had been running on the battery power only and didn't realize it).

the alternator did whine when it was going out. Get it checked someplace or you're gonna be walking [img]smile.gif[/img]

[lord_gufi]

thanks guys yea i tell my dad its the batt, but he doesnt believe me but now he does ( showed him the posts ) see my dad still thinks i dont know **** about cars, so yea, any way imma go buy a new alt and a center off switch, i think you know where thats going
any way l8rz pple