What would you do with this alternator sit.

[JTucholke]

In diagnosing my battery thermal code I took the truck to Autozone for a battery check. As posted in my other post, the batteries turned out to be great (even though almost 5 years old) but the alternator was only putting out 30 amps.

SO...I priced some reman. alternators and found on at Advanced Auto for $139 with a lifetime warranty and is re-manufactured by Delco (Chebby people rejoice). Put it on last weekend. I then had Advanced check the alternator with their system (different than AZ's).

I've read in other posts that sometimes these testers get confused on our trucks. Well, Advanced told me it didn't look like I was getting a charge with my new alternator. I restarted the truck, ran the test again, and then it did get a charge on my gauge, but it wasn't great with the tester. Weird. He then took my old alternator and tested on the bench only to find out it looked fine. When driving the truck later it looked like I was getting a solid 15 amps from the gauge with the new alternator (batteries were a little low). I'm not sure why the batteries were low, but it could be my old alternator.

One thing I have noticed is sometimes it takes a couple minutes for my gauge to show I'm getting a charge of like 15 amps. Others notice this too?

Now, this isn't a horrible job, but I've already put this one on and it has a lifetime warranty.

Should I put the 5 year old one back on? Any ideas why it takes a couple minutes for a charge to seem to appear?