Low voltage issue?
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Now explain it to me, how alternator can be damaged by lower battery voltage?
I am still learning about FICM, but lot of owners use those truck in sub-freezing temperatures, so after long prewarming and long cranking the batteries are likely well below 11v for few minutes till the alternator do its thing.
If 11v is so danger for FICM the cold weather users would have it gone 10 times a season?
I am still learning about FICM, but lot of owners use those truck in sub-freezing temperatures, so after long prewarming and long cranking the batteries are likely well below 11v for few minutes till the alternator do its thing.
If 11v is so danger for FICM the cold weather users would have it gone 10 times a season?
I also have the b@stard post-cycle "Buzz" flash which is known for it's cold blooded characteristics.
You need to eliminate the short trips and use a battery tender if you plan to have the truck sit for extended periods of time.
You've already proven your batteries are toast. Next in line are the FICM and alternator.
Josh
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Joined: Mar 2013
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I do own 40 years old alternator in my motorhome, that I am using for powering roof AC at 1500W AND recharging 400 lb of batteries in 3 banks and it have not failed yet.
After boiling coffee and roasting chicken wings for 3 days of camping the batteries take quite a bit to recharge.
Lead Driver
Joined: Oct 2010
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From: Ouray, CO
I have been seeing low voltage on my Scan Gauge after start up. It has been in the 20 deg F lately and I have been driving my truck to work. I have not been plugging it in at that temp as it starts pretty good.
I noticed on Monday that when I started the truck it turned over slowly but thought it was because it had sat for 8 days. Next morning started it and it started good but the voltage on scan gauge was 10.9 volts. It sat at that voltage and then crept up a little until the high idle kicked in and then it went to 13.6 volts.
I have been watching it and pretty much same every morning. Was at work 12 hours yesterday and started it and drove it to put in fuel, (10 min run time) filled up tank and it turned over very slow but started. Voltage read 9.8 volts but went up quickly. Drove home (15 min) and shut off, checked volts with koeo and it was 12.4 volts. Load tested both batteries (two yrs old) and load tested good.
Sorry for the novel but is my alternator going or somthing else or normal?
I noticed on Monday that when I started the truck it turned over slowly but thought it was because it had sat for 8 days. Next morning started it and it started good but the voltage on scan gauge was 10.9 volts. It sat at that voltage and then crept up a little until the high idle kicked in and then it went to 13.6 volts.
I have been watching it and pretty much same every morning. Was at work 12 hours yesterday and started it and drove it to put in fuel, (10 min run time) filled up tank and it turned over very slow but started. Voltage read 9.8 volts but went up quickly. Drove home (15 min) and shut off, checked volts with koeo and it was 12.4 volts. Load tested both batteries (two yrs old) and load tested good.
Sorry for the novel but is my alternator going or somthing else or normal?
It sounds like they need to be replaced.
2 new batteries produced a HUGE difference for me.
You risk damaging your FICM if you don't fix it !
My voltages now (it was 46* this AM) immediately after a cold start
WITH GP on - is now 11.7..
However (although unlikely) it could also be a poor connection
which reduces the alternators ability to adequately charge the batteries...
I'm in FL, and we rarely get below 50 in the "winter".
Still, my prior batteries would give slow crank after sitting for
the weekend, I noticed my voltage (analog voltage gauge wired to
under-dash fuse panel) would drop to 10.4-10.7 "sometimes".
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