What can cause my alternator to do this?

**Firebirdformula** · 06-18-2010, 09:08 AM

When i first start my car in the morning my charging gauge stays low and will stay low until i rev it to 2k rpms and then when i drive it drops once and then charges fine throughout the day ?

**BLK2KSS** · 06-18-2010, 10:56 AM

Do you have under drive pulleys? They cause your accessories to turn at a lower rate which can cause this. When revving at a higher rpm, they are turning more at the speed they are supposed to therefore charging it back up. Unless you keep it at a higher rpm for long enough for it to charge right then the juice will fall back down.

**Firebirdformula** · 06-18-2010, 01:58 PM

no everything is completely stock....and when i rev it to 2k and let off somethin kicks it on because the engine goes under a load it sounds like, and the rpms drop jus a little

**35th-ANV-SS** · 06-18-2010, 03:07 PM

Free bump in hopes a mod might see this and move it to the appropriate section of the forum where you might see more responses. Not too many people troll the stereo and electronics section. You probably want to shoot for external engine or something along those lines.

**Firebirdformula** · 06-18-2010, 03:32 PM

ok man thanks ill move it

**KMdef9** · 06-18-2010, 06:00 PM

Take the alt. off and take it up to the auto parts store and have them test it. Unless you have one already...

**rsg98Z28** · 06-24-2010, 06:33 PM

sounds like the voltage regulator, its on the alternator usually when the regulator goes bad u need to replace the entire alternator

**JaycenK** · 06-24-2010, 08:16 PM

Originally Posted by rsg98Z28

sounds like the voltage regulator, its on the alternator usually when the regulator goes bad u need to replace the entire alternator

I second the regulator.
Just change the regulator and even change the bearings while your in there. You will thank me as I should have taken my own advice as I am now on my 4th one from the parts stores.

**Firebirdformula** · 06-26-2010, 10:56 AM

ya i took my alternator back to the guy who rebuilt it and he fixed it for free, and on the way home i teated it at oreillys haha three times jus to make sure when i put it on for the 5th time now!!!!!!! it woruld woprk, and everything is workin i revved it to 4 grand and it didnt drop at all

**qwik219d9** · 06-27-2010, 03:58 AM

from what I've read about alternaters when it stops charging replace the alt.

w/ a brand new alt.

w/ rebuilt plan on continuosly replaceing fquently.

**rsg98Z28** · 06-29-2010, 07:14 PM

Originally Posted by qwik219d9

from what I've read about alternaters when it stops charging replace the alt.

w/ a brand new alt.

w/ rebuilt plan on continuosly replaceing fquently.

I agree!!

**Smittro** · 06-29-2010, 07:23 PM

Originally Posted by qwik219d9

from what I've read about alternaters when it stops charging replace the alt.

w/ a brand new alt.

w/ rebuilt plan on continuosly replaceing fquently.

Originally Posted by rsg98Z28

I agree!!

+3

**duweller** · 07-04-2010, 06:00 PM

my altenator does the exact same thing I keep an eye on it through out the day. I just replaced the battery because the last one just died on me so I might need to replace the altenator next I think like 14v is charging? and sometimes it stays just a hair above 13 for a long time