New alternator whining

[Electrician]

Return the alternator, and get a name brand alternator.

I am. I already started the return process for Amazon, but I gotta wait til Saturday to actually unbolt it and go drop it off at a UPS store. My brother is gonna let me use his alternator off his 5.3 that's sitting right now. That way I don't have to spend money on another one until I get my refund. The 145amp AC Delco is already in my cart. Same price too

 

[Electrician]

AC Delco 145amp is ordered and will be here in a few days. Now I can get going on finding the stuff to rebuild my other one. Voltage regulator and rectifier assembly for sure and probably should do the smart thing and replace the bearings too. My brother told me something I never thought about when I was swapping on his alternator to borrow is that you're not supposed to use compressed air to blow out an old alternator. After years of heat, the thin coating on the windings gets brittle (but remains in place and still works most of the time) but blowing it with compressed air can strip off some of that coating to where it may not work properly. Interesting...

 

[Roll On]

I went through three alternators from different auto parts stores, all were rebuilt , finally gave up and paid double the price for a new one from the dealership, put it in and done.

 

[Doubeleive]

later on down the road if you decide to upgrade to a higher output the mechman as already mentioned is a great option, they take about 30-45 days or so to get to your door because they are built to order, mine has been on now for about 50k puts out 15v like a champ most of the time, the RVC controls that based on the battery temperature.
they are pricey though, they make different versions based on the rpm I wouldn't get one that restricts the max rpm's unless you really needed it that way for a special purpose.
the difference is the pulley size used generally, larger pulley for more output at low rpm's which means it can only be revved to xxxx rpm's without possibly ruining it.

 

[Doubeleive]

and to answer your other question, no more output does not mean it would make it whine, either it has a internal defect or there is a ground issue, sometimes a ground isolator will resolve that issue but it shouldn't be needed on a modern vehicle

 

[Electrician]

I know that one I just sent back was defective. I swapped in my brother's USED alternator and now it's running fine, no whine. I'll post up on how it goes with the AC Delco from Amazon. I read there's been some issues before with sellers having fake products on Amazon. Anyone had that experience with Amazon before? I haven't (knock on wood)

 

[Doubeleive]

I know that one I just sent back was defective. I swapped in my brother's USED alternator and now it's running fine, no whine. I'll post up on how it goes with the AC Delco from Amazon. I read there's been some issues before with sellers having fake products on Amazon. Anyone had that experience with Amazon before? I haven't (knock on wood)

YA, if I buy any oem parts off amazon I make sure it's the ac delco store, most of the fake stuff is smaller like knock sensors or spark plugs, bigger stuff is hard to replicate and still be profitable, other thing to watch for is bait and switch where they advertise it very much like a oem part but it's not.
then on the other end of the spectrum you have companys like "herko" that sell oem as there own brand

 

[afpj]

I read there's been some issues before with sellers having fake products on Amazon. Anyone had that experience with Amazon before? I haven't (knock on wood)

yep, Last year I ordered a Delphi MAF as well as KYB shocks, they were both fake. The shocks may have had a bad batch of bushings, but just the packaging was different compared to the KYB box I got from rock auto. It ended up Rockauto being actually a few dollars cheaper too including shipping.

 

[Electrician]

RockAuto is a blessing for sure. My brother who's been a mechanic his whole life swears by them. He just doesn't like buying: 1)core-in parts or 2)wear parts that will likely fail before warranty expires, because the shipping process is too much hassle