Electrical - where to begin

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Baja_Bob

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If I understand you correctly, if the rectifier in the alternator is leaking ac then it won’t be supplying enough voltage to charge the battery?
The alternator produces AC voltage, the rectifier in the alternator turns it to DC volts that the vehicle uses. If the rectifier was bad it would send AC voltage into the battery and vehicle systems. If you get 13-15v DC output from the alternator, it works properly.

I don't mean to add any more confusion to your original problem.
 
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Moosemoon

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The alternator produces AC voltage, the rectifier in the alternator turns it to DC volts that the vehicle uses. If the rectifier was bad it would send AC voltage into the battery and vehicle systems. If you get 13-15v DC output from the alternator, it works properly.

I don't mean to add any more confusion to your original problem.
No added confusion. Additional explanation is welcomed and in my case often necessary. Based on that alternator is good - doing it’s job.
 
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Moosemoon

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Have you actually load tested the battery or had it checked?
Have tested battery thru my scanner - it does more than report DTCs. No starting issues. Lights strong when just running off battery. Think that part is good.
 
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Moosemoon

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Could a faulty crankshaft sensor lead to getting the knock sensor code? I would think crankshaft sensor would have it’s own code but just thought I’d throw that to those who know waaaay more than I do.
 

treehan77

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I would be questioning the knock sensors since that is the code you are getting. It is recommended to change the brittle harness when they are replaced.
 

treehan77

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You can at least check each one for resistance with your multimeter. You can do a rudimentary function check since they should create AC voltage also. Maybe your meter has a “remember peak” setting and you can test each sensor and compare. Keep in mind your results could be the knock sensor itself or the harness could be bad
 
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Moosemoon

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I would be questioning the knock sensors since that is the code you are getting. It is recommended to change the brittle harness when they are replaced.
The harness was replaced with the knock sensors. One set o’reilly; latest AC Delco .Dealer says they are working. There are other codes suggesting some electrical issues and now the radio will not turn on. Instrument panel light is dim - brightened once when I hit just the right bump.

HOWEVER, I’ve read that 50% of ac delco sensors are also bad out of the box. Have no idea if mechanic(s) tested ks before closing up and hoping for the best.
 
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Moosemoon

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You can at least check each one for resistance with your multimeter. You can do a rudimentary function check since they should create AC voltage also. Maybe your meter has a “remember peak” setting and you can test each sensor and compare. Keep in mind your results could be the knock sensor itself or the harness could be bad
I watched that video this morning. But cold, windy, and snowing here so that adventure will have to wait for a warmer day.
 
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