Intermitant voltage drops, car sputters

Anger.Engineering

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I am ready to pull my hair out. I have a 97 GT, I just completed power tour, and Saturday when I start my car my voltage drops, bounces between 8 and 10 (aftermarket volt gauge) car spits sputters backfires doesnt want to run. I replaced the alternator a week prior, had zero issues for a week and 2200 miles. Battery was replaced 3 mos ago. I pull the alternator fuse and it STILL does it. Like I said this JUST started and I cannot figure out WTH is going on. Need advice.. Im too irritated and not thinking straight. Thank you
 
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cobrajeff96

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Definitely check all grounds as a first measure. You can do an ohmeter test from alternator case to the negative terminal of the battery and see what it reads.
 

Miltoid

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You are losing battery power. It could be something as simple as a corroded or loose battery terminal. What happens if you put a heavy load on it? Turn on headlights, high blower etc. engine not running. Check the voltage at battery terminals, it should be 12 volts. Are the headlights dim or off? Check for voltage drop from positive to block. Check for voltage drop across positive battery cable.
 
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Anger.Engineering

Anger.Engineering

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Have done all of that. Most of the time with lights, ac and radio work fine. Cables are tight. Battery voltage when off is 12.8. 13.7 at battery and output of alternator when running (all checked with voltmeter). It just periodically will start cutting out. Sometimes I let it sit, it works fine. Others it continues to cut out. It is so random it is hard to repeat conditions because no matter what I try, sometimes it works sometimes not

I have pulled the alternator fuse and it still intermitantly cuts out/down to 8. I am thinking I am going to have to wire trace/look for a broken wire
 

RAU03MACH

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harness from alt to driver side plug ins could be loos connection
ther are also some ground wire like 16 gage on apron above head light black
make sure grounded good
there is also a small barrel looking fuse holder beside battery this is not afuse but a connection
make sure they are clean
 
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Anger.Engineering

Anger.Engineering

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harness from alt to driver side plug ins could be loos connection CHECKED
there are also some ground wire like 16 gage on apron above head light black CHECKED
make sure grounded good
there is also a small barrel looking fuse holder beside battery this is not a fuse but a connection Will check tonight
make sure they are clean
 
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Anger.Engineering

Anger.Engineering

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Checked the barrel connection, was very corroded. I had to pull the battery tray to locate it. Seems to have helped, my volt meter shows 14 volts now, havent tried driving it much to verify if that was the issue, or a coincidence.
 

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