Lagonia

I am thinking this points to an alternator issue? May be part of the rectifier bridge is toast? Once the RPMs increase, the fluttering goes away and do return when the RPMs drop to idle... thoughts?

DUB

BINGO...that is where I would start or at least verify all connections are secure.

I have found that sometimes it is a loose wire or partially broken wire that at idle is not making contact...but when the engine moves it joins back and the wire comes back together.

DUB

Big2Bird

My money is on the regulator. Test it all.

lvmyvt76

you can rebuild that alternator yourself, especially if it is original, just go O'reilly's and get the needed parts , go on line to search a video to rebuild it, doesn't take many tools, just mark the case so you don't change the clocking of it. They can also check your alternator off or on the car, but watch who you let check it!! maybe take it to 2 or 3 places , or to a shop that rebuilds them professionally.

Lagonia

A rebuilt alternator from O'Reilly has fixed this problem. No more light or voltmeter flutter. Yay!

jb78L-82

I personally would rebuild the OEM alternator now (hopefully you did not exchange it). Electrically rebuilt alternators, starters, etc are junk most of the time and, in my experience, will ultimately fail, prematurely, since you have no idea when it was "rebuilt", what exactly was changed...they do NOT change all the components on rebuilt electrical units.

I stopped using rebuilt electrical components about 20 years ago as long as I can source the part new, which usually you can, and the cost difference is not much more than a rebuilt, in many cases. Oh I don't care about lifetime warranty's since an alternator/starter failure can be VERY INCONVIENENT and dangerous, depending when they occur. I don't care if O'Reillys or Autozone warranty's their rebuilt junk.......

I replaced the C3 alternator with NEW CS144 140 amp unit 10 years ago and still going strong. Also, a new alternator and new starter on my daughters 2001 Grand Prix (bought new in 01) both of which have 100,000 and 130,000 miles on the new units......

DUB

when it comes to buying a part form an auto parts store. I just do not trust them. I have had customers at the auto parts store and call me and when they pull a part right out of the box and test it...it does not work.

Now I do not take the time to rebuild alternators and starters due to I have a great rebuilding service company that does it for me....and it is actually a better cost ratio for my customer due to my labor rate. And at least I KNOW what has been done and it is RIGHT!

DUB

Lagonia

I still have the original one - not clear, though, if indeed it is the original one or one that has been swapped before - are there any tell tale signs I should look for? If not the original, not worth keeping it, I don't think. I appreciate your opinions greatly.

lvmyvt76

should be numbers on the alt to identify it. take pictures and put them on here, someone will chime in on what it is.