Power interruption error code 5A - Page 2

X5chemist · #11 02-07-2022, 12:47 PM

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.

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andrewwynn · #12 02-07-2022, 04:56 PM

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.

puddinboo · #13 02-07-2022, 05:17 PM

Checked both boost cable fire wall side and engine side ,both are good and tight.

Quote:

Originally Posted by andrewwynn

Because you aren't checking b+ while driving however there is one more possibly that lines up with some of your symptoms:

B+ bolt loose. Lift the cover over the aft side of the firewall and check if the bolt going through to b+ is loose. It's how I disconnect power when working on starter/alternator and 1-2x a year somebody on xo discovers their B+ bolt is loose

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puddinboo · #14 02-07-2022, 05:25 PM

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?

Quote:

Originally Posted by andrewwynn

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.

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andrewwynn · #15 02-07-2022, 05:51 PM

Quote:

Originally Posted by puddinboo

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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puddinboo · #16 02-07-2022, 07:35 PM

I replaced it about 60000km ( 6 yrs ago) with a Bosch remanufactured 1.

Quote:

Originally Posted by andrewwynn

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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Sent from my SM-G781W using Xoutpost.com mobile app

workingonit · #17 02-07-2022, 08:17 PM

Quote:

Originally Posted by andrewwynn

... I've never seen a working alternator drop below 13v at any RPM.

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!