Battery Light
More Turbo
Joined: Mar 2007
Posts: 636
Likes: 7
From: La Mesa, Ca.
Check the connections at the alternator, there have been a number of our trucks that have connection issues and get the same symptoms. You should be getting 14.5 vdc even at idle on a warm engine.
Posting Guru
Joined: Apr 2009
Posts: 2,447
Likes: 1
From: Northern Idaho
correction, 13.8v to 14.5v at idle once it has been started for at least 1 to 2 minutes, I know because I have a Volt meter on my pod and it starts at 12v when I start the truck and rises to 13.8 or 13.9 after a minute or two of idling first thing in the morning. Now if I park the truck after running for a while and come out, start the truck and take off, because I'm getting more RPMs it'll jump up to 13.8 to 14.1 pretty quickly, within about 5 to 20 seconds.
Bottom line, 13.5 or less after idling for 2 minutes or a fluctuating voltage is bad, anything above 15v is bad and for each volt you go up it gets worse. 18v is CRITICAL!
Bottom line, 13.5 or less after idling for 2 minutes or a fluctuating voltage is bad, anything above 15v is bad and for each volt you go up it gets worse. 18v is CRITICAL!
Cargo Master
Joined: Jun 2003
Posts: 3,292
Likes: 6
From: Ardenvoir, Washington
This is because your glow plugs are drawing the voltage down to around 12v for the 1st minute or so... So yes.. you should wait a minute or so after a cold start..
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Posting Guru
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From: Northern Idaho
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Posting Guru
Joined: Apr 2009
Posts: 2,447
Likes: 1
From: Northern Idaho
I told you I would get you a video, but I got two instead and yes you are right, during a cold start with the GPs on it sits at 12v then jumps up, but during a warm start there is a little surprise.....
Here is a cold start...
http://s833.photobucket.com/albums/z...019_122138.mp4
Here is a warm start...
http://s833.photobucket.com/albums/z...019_133923.mp4
Here is a cold start...
http://s833.photobucket.com/albums/z...019_122138.mp4
Here is a warm start...
http://s833.photobucket.com/albums/z...019_133923.mp4
Thread Starter
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Mountain Pass
Joined: Apr 2009
Posts: 225
Likes: 5
From: Colusa
Thanks Guys
I just wanted to say thanks. I got home from work last night, made it Kragen before 9:00pm Barely and put in a new altenator. Everything is working fine now! Thanks for the help! :-)
Cargo Master
Joined: Jun 2003
Posts: 3,292
Likes: 6
From: Ardenvoir, Washington
This thread is complete after he replaced his alternator... you probably should start a "new" thread for better response.. You could have your alternator checked for free at one of many auto parts store however.. I would double check the voltage after waiting about 2 minutes at the batteries with a volt meter 1st..should be around 14 volts..
