Squeak from accys, pull belt, no squeak. Alt is relatively new, spins free, AC pulley spins free, tensioner hitches & makes tiny noise. Rpl tensioner. No change in noise when ac cycles.
Store replaced alt under warranty.

Now ALT DOES NOT CHARGE.

Had it in and out repeatedly, chk'd fuse & mega fuses at power block, connector does not appear damaged. Have 12 v on red wire @ alt.
Took alt to store, tested good. Took car to local shop, they think it is the alt.

Any ideas?

2010 3.0 V6

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Store waranteed alt again, no change


Cables are good, terms clean & tight.

Code P0620, Generator Control Circuit.

PIDs Gen Command Line Fault
Generator Fault Status Yes
Gen Monitor Line Status Fault High
I get battery voltage when engine is running. Batt Light comes on.
If I rev it up to about 3k it will start charging at 13.8v which apparently is a failsafe mode. It always ran at 14.5 to 14.7 before.


Have 12v @ stud to battery.


I cannot reach to probe 3 wire connector when connected to alt.

Disconnected I read

KOEO KOER

red/brn 12v 12v

grn/or .06v 1.9v

Purp 12v 12v

Took it to an auto electric place purported to be the best in the area by someone I respect. The owner told me they do not believe the alternator is a quality part (from a national chain).
He said "Yes we are here to make money, but not by ripping anyone off" "save yourself my markup and labor charges" "The first thing I will do is replace the alt so go get one from NAPA and replace it".

Unfortunately that did not fix it. I am getting concerned that this may be a PCM issue.

Any thoughts?

 

By chance, have you considered following the step-by-step diagnostic procedure in the factory service manual?

 

I have the Helms manuals for several of my cars but not this one...