Alternator problems after knock sensor replacement

[Blackmar401]

2003 tahoe 4.8, So I'm not a big car guy and this is probably the biggest repair I have taken on. Got the knock sensors in and actually snapped a stud putting it back together. Torque wrench only went to 10ftlbs. Anyways, I welded a bolt to it and backed it out and continued on. Snapped the pcv tube so I replaced the valve(seems to be missing something, new one is empty and old one has guts that move around)Reattached everything and started it up. Ran like it was before for a few minutes then seemed to get smoother. Idled for like 10 or 15 minutes then drove it for 5. The wife then noticed the battery light and the screen saying battery not charging. When the battery is connected to the car and I try to charge it the charger lights up "bad battery" when I disconnected it suddenly it would charge. I was getting like 8v at the battery and alternator. The middle brown wire (watched a video saying this should read like 14 when running) on the alternator also reads the same . I remember seeing the battery light I think right before starting the repair but I'm not 100%. so basically I'm wondering if I could have broken a wire(it was like 20 degrees and raining/snowing while I did the repairs. I broke a bunch of the gray clips on the injectors but they seemed to reconnect no problem. Is it more likely that it's just a coincidence and the alternator failed right before or during/after the repair. We really need this vehicle on the road but I don't want to just buy an unneeded alternator and or battery as I'm already like $700 into this with ac Delco sensors, new gasket and tools that I needed. Any suggestions would be greatly appreciated.

 

[rockola1971]

First make sure the battery is fully charged (battery charger) then start the Tahoe up and check battery voltage at the BATTERY (this voltage reading will be the alternator output voltage). You might want to also check the large gauge wire coming off the back of the alternator (red/pink) which goes to the positive terminal of the battery (this is the connection that allows the alternator to charge the battery). Inspect for damage to the wire, wire pinched by engine valley cover, etc.

 

[Miami-Dade]

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