Mine idles with a 12V cigarette Bluetooth adapter reading 13.8V at idle. Old and new alternator read the same. It's above 14 after starting for a short while. I prefer 13.3+V on any modern vehicle.

Idle not the problem. The voltage dip is usually worst when coming off throttle to coast to a stop. Any time I've had a weak alternator that's when I had the voltage dip.

Checked both boost cable fire wall side and engine side ,both are good and tight.Sent from my SM-G781W using Xoutpost.com mobile app

I unlocked my cluster and read voltage directly from it here is my results.

Vehicle in park I get 13.3-13.7 v (850 RPMS)
Vehicle in drive 12.2v - 12.5 v (630 RPMS)
When I'm stopped fully at a light I get the low readings,when I take off I get the normal readings like when in park.
I reset my Code 5A reading and took the X for a drive and no code or the 3 orange lights as of now.
I am concerned my Alternator isn't put out enough voltage while in drive? Or is this normal?Sent from my SM-G781W using Xoutpost.com mobile app

You are right to be concerned. Your alternator is not putting out proper voltage at idle. I've never seen a working alternator drop below 13v at any RPM.


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I replaced it about 60000km ( 6 yrs ago) with a Bosch remanufactured 1.Sent from my SM-G781W using Xoutpost.com mobile app

Old-time alternators had to get up to a minimum set speed
 

Then you've never had a 10DN alternator (GM) with an external regulator. When I first got my old 327 Chevelle, it had that alternator, and when idling at 600-700 in drive, the battery would drain to under 12.5vdc consistently.

I would put it in neutral and rev it 'til the alternator would kick in, but that was my temporary solution. I moved up to a 105 amp one wire alternator, which worked fine until I got serious about drag-racing, went to a big-block 427, and used a 140 amp alternator (with deep-groove pulleys).

But, after continually throwing belts at 7200+ rpm (and disintegrating a rod at 7400 rpm when the limiter failed), I switched to a bigger/badder 427 with dual batteries and charging between rounds. No more alternator problems. P.S. that 14:1 compression BBC would rev all day to 7200, and still lives after 100's (1,000's?) of rounds (but now traded for my X5). Sniff!

Warranty on that bad boy?


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Only 2 yrs. I should have got it from FCP lol.Sent from my SM-G781W using Xoutpost.com mobile app

I bought mine from O'Reilly. Lifetime warranty. Had to use the warranty to exchange it also