battery voltage fluctuating
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Mountain Pass
Joined: Nov 2012
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battery voltage fluctuating
I have a 13 f350 6.7, weight loss with proven tunes.
One of the things I monitor on my ezlynk app is battery voltage. I usually have 14.4 running, past month or so I have noticed it slowly drop (seems like it drops with higher rpms) to as low as 13.7.
It has been a steady drop, for awhile it it was 14.3-14.2, then 14.2-.1 and so on. I cleaned my battery terminals to see if that would help, I got 12V at both batteries with them disconnected from the truck.
Some background on the truck, I bought it in august (emissions were intact at that time) . Shortly after I bought it I was getting an intermittent battery light, which soon turned to a steady light. Dealer sent me to a local shop (dealer is in a different town) that replaced alternator with a FOMOCO part as it was diagnosed with a bad diode, they also rerouted an alternator wire from my understanding. (this work was 21ishK miles ago)
Has anyone else experienced this issue?
Thanks in advance!
One of the things I monitor on my ezlynk app is battery voltage. I usually have 14.4 running, past month or so I have noticed it slowly drop (seems like it drops with higher rpms) to as low as 13.7.
It has been a steady drop, for awhile it it was 14.3-14.2, then 14.2-.1 and so on. I cleaned my battery terminals to see if that would help, I got 12V at both batteries with them disconnected from the truck.
Some background on the truck, I bought it in august (emissions were intact at that time) . Shortly after I bought it I was getting an intermittent battery light, which soon turned to a steady light. Dealer sent me to a local shop (dealer is in a different town) that replaced alternator with a FOMOCO part as it was diagnosed with a bad diode, they also rerouted an alternator wire from my understanding. (this work was 21ishK miles ago)
Has anyone else experienced this issue?
Thanks in advance!
Laughing Gas
Joined: Sep 2018
Posts: 1,115
Likes: 264
From: KY
My new 2020 F350 6.7 with the dual alternators fluctuates 13.7-14.5. I believe most modern vehicles use "smart" alternators that can vary the voltage and current based on demand. I'm not sure if the 13 had those but it wouldnt surprise me
New User
Joined: May 2021
Posts: 8
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Batteries and alternator output.
a shorted cell will effect output of the alternator. And performance of the vehicle
New User
Joined: May 2021
Posts: 8
Likes: 0
I have a 13 f350 6.7, weight loss with proven tunes.
One of the things I monitor on my ezlynk app is battery voltage. I usually have 14.4 running, past month or so I have noticed it slowly drop (seems like it drops with higher rpms) to as low as 13.7.
It has been a steady drop, for awhile it it was 14.3-14.2, then 14.2-.1 and so on. I cleaned my battery terminals to see if that would help, I got 12V at both batteries with them disconnected from the truck.
Some background on the truck, I bought it in august (emissions were intact at that time) . Shortly after I bought it I was getting an intermittent battery light, which soon turned to a steady light. Dealer sent me to a local shop (dealer is in a different town) that replaced alternator with a FOMOCO part as it was diagnosed with a bad diode, they also rerouted an alternator wire from my understanding. (this work was 21ishK miles ago)
Has anyone else experienced this issue?
Thanks in advance!
One of the things I monitor on my ezlynk app is battery voltage. I usually have 14.4 running, past month or so I have noticed it slowly drop (seems like it drops with higher rpms) to as low as 13.7.
It has been a steady drop, for awhile it it was 14.3-14.2, then 14.2-.1 and so on. I cleaned my battery terminals to see if that would help, I got 12V at both batteries with them disconnected from the truck.
Some background on the truck, I bought it in august (emissions were intact at that time) . Shortly after I bought it I was getting an intermittent battery light, which soon turned to a steady light. Dealer sent me to a local shop (dealer is in a different town) that replaced alternator with a FOMOCO part as it was diagnosed with a bad diode, they also rerouted an alternator wire from my understanding. (this work was 21ishK miles ago)
Has anyone else experienced this issue?
Thanks in advance!
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Cargo Master
Joined: Feb 2020
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A shorted cell sure, but not necessarily due to old age...
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Hotshot
Joined: Jul 2013
Posts: 14,302
Likes: 2,197
I had the battery light problem and the infamous wire by pass done by the dealer fixed it.
my battery voltage on new batteries are low 14's on start up and mid 14's after the engines run for a few minutes.
my recomendation is just to have your batteries tested for cranking amps...can be done at any auto parts store.
my battery voltage on new batteries are low 14's on start up and mid 14's after the engines run for a few minutes.
my recomendation is just to have your batteries tested for cranking amps...can be done at any auto parts store.
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