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weak alternator causing random low fuel pressure?

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Old 02-23-2020, 02:03 PM
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Default weak alternator causing random low fuel pressure?

I noticed a few times over the past month lower than normal fuel pressure. one day it will be right at 58 psi then it might drop a few psi and one day it went down to 50 psi. I am running twin pumps so I thought maybe one went out but the next day things were fine so I thought maybe the gauge or pressure sensor might be going bad. today I was on a long drive and I noticed my alternator voltage was under 14 v, usually its a little over 14v. if the voltage is randomly dropping could this cause fuel pressure issues? I am assuming yes and think this may be my problem but just seeing if anyone has dealt with this issue.
Old 02-23-2020, 03:26 PM
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I can't remember if your truck is an 04 or 05? But the later model NBS trucks had voltage regulation that drops the voltage during normal operation. Both my trucks will sit around 13.5v unless the headlights are on, which always makes it stay above 14v
Old 02-23-2020, 03:31 PM
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It is an 05 but i do not ever recall it being under 14, it always sits just above 14. I always monitor oil pressure so i always look there.
Old 02-23-2020, 07:18 PM
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My 06 is variable.
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