Alternator going?

[kknobl]

I've noticed that after my car sits over night, the voltmeter is showing around 14.5 - 15.

 

After some driving around, it will slowly drop to 13. At idle it tends to fluctuate just a little bit, but when I have my turn signals on, the fluctuations become more obvious, particularly with the headlights on...

 

Any ideas?

 

Thanks,

Kevin

[Supreme Cutlass]

What engine do you have?

[DiscoStudd]

Try tightening down all of your battery cables first, especially the Auxillary Positive terminal...

[supreme_style21]

Sounds like a normal w-body thang.

[1990lumina]

I'd use an actual voltimeter (even a cheaper one) and test it with that that....it's a long shot, but your guage could be messed up too.

 

I'd put my money on alternator. All you lucky guys get advanced warnings before your's goes. I get 5 second warning and DEAD! lol

[kknobl]

What engine do you have?

 

Sorry - 3.1 MPFI...

 

Kevin

[DOHCRagtopguy]

Dude, get a voltmeter and check the charge under a full load (lights, a/c, etc).

 

It should be charging at least 13.5 volts. Watch the voltmeter for a few minutes under load. If the voltage drops slowly, the alternator is on its way out.

 

Be glad you have the 3.1, piece of cake to change!

[OldSkoolGP]

My alternator on my 3.4 did that to me for two years, but when it got really wet out at times it just stopped working all together. Even my 160 amp alternator does that today. By chance do you have an underdrive pulley installed?