Is my alternator going bad?

[clipse0001]

Hey,
Yet another thing I found wrong with the devil GST of mine. When I turn on high beams the idle seems to stumble down. When i turn on the AC it drops to 450 or so. When the tach says that the idle is at 450 and I can feel the engine shake at idle, the logger says that the idle is at 750. Whats up with that? I just replaced all the vac lines and it helped idle a bit but its still annoyeing.

-Anton-

 

[majik2k5]

Easiest way to figure this one out is to go over to your local Advanced Auto or Autozone. They'll test your alternator and your battery for free.

 

[wcpierson]

Easiest way to figure this one out is to go over to your local Advanced Auto or Autozone. They'll test your alternator and your battery for free.

hes right or you can go to walmart and pic up a voltmeter for like $15 like i did so you can check the voltage yourself of course i bought the meter before i got my datalogger so i dont really have to worry about it...but anyways yea just go to autozone theyll do it for free...

 

[importboost]

It sounds like one of your diodes went out. No biggie, but if you don't like it id suggest getting a new alt. But of course take their advice and get it tested for sure.

 

[clipse0001]

I had it tested and they said it was fine. I cant figure out what else can cause this.

 

[importboost]

When they tested it, did it put a load on the alt or just test the output of the alt?

 

[clipse0001]

If you are asking if they reved it to 2000 RPM and test it then no, they tested the output.

Anton

 

[importboost]

What were the output numbers? When a diode goes out the alternator can still put out the right amount of amperage until the demand is higher than 2/3's the normal output. Like when you turn your ac on.

 

[DakotaPSI]

Not to take away from the thread, but on my alternator where you hook up the power cord that takes away from the alt. when i looked tonight it was glowing red the bolt and the nut on it???? is this bad?? if so, whats causing it

 

[importboost]

Not to take away from the thread, but on my alternator where you hook up the power cord that takes away from the alt. when i looked tonight it was glowing red the bolt and the nut on it???? is this bad?? if so, whats causing it

Not bad persay, but it's probably that the bolt is loose and making it arch which makes it hot so when it gets hot enough it glows. Try tightening it down.

If you have any more probs pm me or start your own thread

End whore

 

[clipse0001]

What were the output numbers? When a diode goes out the alternator can still put out the right amount of amperage until the demand is higher than 2/3's the normal output. Like when you turn your ac on.

I have no idea on the numbers, but I have a multimeter somewhere. Do you know where to test?

Thanks for the help.

 

[importboost]

I have no idea on the numbers, but I have a multimeter somewhere. Do you know where to test?

Thanks for the help.

With the car running put your positive lead on the pos on the battery, and the negative on the negative post on the battery. Have someone bring the rpms up to bout 1.2k or so and see the reading on the battery. It should be somewhere between 14.6 and 15.2Volts if i remember correctly. Oh also, turn your lights on, radio, ac and anything that takes voltage to make sure you have a good load on it. If a diode is bad you will see bout 2/3's of that.