Alternator / Volt Issue?

So, I'm not 100% sure that I have / had a charging issue. Let me explain. I was driving the other day and my battery light would flicker faintly in the background. Occasionally it would be gone completely, the other times it would be solid on. I checked the voltage output via my scanguage and it was between 13.7 and 14.1, not exactly a warning flag. So i took the truck to get the system load tested at advance auto or autozone i forget which. Battery checks fine (only about 15 months old) and the alternator checks out fine as well, all the while the battery light is off. On my way home, it started to flicker gain.

So i bit the bullet and get a reman unit from NAPA. I had the old unit tested off the vehicle and they tested it in the store 3 times and all 3 times it came back good. So maybe I replaced it for nothing? Threw the new one on the truck and the battery light has been out since Saturday. BUT! Now my volt readout on the scangauge is even more wonky than before. Cruising around its about 13.9 or 14.0, but if I come to a stop at a redlight, it will dip down as low as 12.4 or 12.5 while i'm waiting for the light to change. As soon as I lift my foot off the brake to get going once the light changes, it jumps back up to 14.0 volts. Or like the other day when I had my defrosters on, headlights and stereo going, it would dip down that low again until the compressor would kick on, then it would run back up to that 13.9 or 14.0 volts. Again, no battery light on at all this time and no other indication that the truck is having any issues other than the readout display on the scanguage. I'm I reading into this too much and paying to close of attention to the volt readout?

 

If your idle speed is good (above 550 RPM) it shouldn't quit charging at idle, may just be a shitty reman. Most parts store reman alternators are junk anymore.

 

I guess i should check to see what my idle is too.

 

I got one of those intermittant zero output at idle reman's from OReilly's. I took it back and they said it tested good on their bench so no warranty.
I then bought a new Remy 130A from Rock Auto with no core charge for about the same price as the reman and haven't had any problem since install.
Also check your voltage at the battery if you can as the scanguage may be reading slightly different.

 

Thats on my list to do this weekend, get out there with my voltage reader and test to see what comes up rather than relying on the scangauge.

 

Here's a video I took to show the issue. I have the description in the video, but here is the gist of it.

https://youtube.com/shorts/wqdfchT9eME?si=n8RTNL84C1VdJFSi