Voltage Idiot Light
Thread Starter
|
Senior User
Joined: Nov 2004
Posts: 147
Likes: 0
From: Upstate NY
Voltage Idiot Light
Maybe someone can help? It seems that when I first start my truck the voltage light seems to come on stady sometimes and then other times it flickers. I checked the voltage at the aux pcm it reads 14.4 at idle at start up. Just for kicks the next morning I checked it at the batteries and it also read 14.4. I just replaced the alternator last summer so it probably has about 20,000 miles on it at most. But I dont think that that is the problem with the voltage readings. Has anyone else had this occur. I dont want to be out on a trip and have something fail. Thanks
Senior User
Joined: Sep 2006
Posts: 258
Likes: 5
From: NorCal
Your batteries should not read 14.4 when the engine is off. It should be around 12.8V or so. Did you check the votlage with the engine off? When the engine is on the alterator bumps your voltage to 14.4V to charge them up.
Last edited by ebbnflow; Apr 13, 2007 at 04:25 PM. Reason: added more
Thread Starter
|
Senior User
Joined: Nov 2004
Posts: 147
Likes: 0
From: Upstate NY
oh, sorry that is with the truck running, and it is at 12.6-12.9v, with the truck not running. Is their a sensor somewhere that can be replaced or is it in the alternator? Thanks
Thread Starter
|
Senior User
Joined: Nov 2004
Posts: 147
Likes: 0
From: Upstate NY
ok, thanks i will check that. Last night it happened again and thier seems to be a draw on the system as the head lights dimmed a little but the volatge didnt drop below 14 volts. After the lights were bright again the voltage light went out, any ideas on what could be causing a draw with the engine at op. temps?
More Turbo
Joined: Feb 2004
Posts: 509
Likes: 3
From: Findlay, Il
Trending Topics
FTE Leadership Emeritus
Joined: May 2001
Posts: 13,653
Likes: 6
From: Cabot, Arkansas
Originally Posted by Brian0445
ok, thanks i will check that. Last night it happened again and thier seems to be a draw on the system as the head lights dimmed a little but the volatge didnt drop below 14 volts. After the lights were bright again the voltage light went out, any ideas on what could be causing a draw with the engine at op. temps?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Thread Starter
|
Senior User
Joined: Nov 2004
Posts: 147
Likes: 0
From: Upstate NY
I just replaced the batteries last winter about 3 months ago with mastercraft batteries, 3rd set and I am happy with them. I think cookie88 hit the nail right on the head about the voltage regulator.... This will be the 3rd rebuilt alternator in 2 years. When I replaced the alternator the first time i wanted a new one from ford, they had only one, brought it home and noticed that the box had been droped and the shaft and pully wouldnt turn so I got a reman from the local parts store (carquest). I truly belive that they have a bunch of retards rebuilding these things, or they just replace the broken components. I got the 2nd replacement at no charge but it is stupid to keep changing junk with junk, even if its free. Guess Ill call the local stealership to get a price quote.
Elder User
Joined: Aug 2006
Posts: 870
Likes: 0
From: Mountaintop, PA
Wouldn't by disconnecting the red batt cable going to each battery, THEN testing each battery individually, give you a better reading on each one. I was understanding that with the red batt cable connected across the two will allow a trickle to and from each one. This way you can find a dead batt out of two. Just wanted to make sure you are doing it right.
Posting Guru
Joined: Apr 2000
Posts: 1,345
Likes: 0
From: NorCal
Originally Posted by Brian0445
Maybe someone can help? It seems that when I first start my truck the voltage light seems to come on stady sometimes and then other times it flickers. ... Has anyone else had this occur. I dont want to be out on a trip and have something fail. Thanks
Junior User
Joined: Feb 2005
Posts: 53
Likes: 0
From: Alberta
Check the small connector on the top of the alternator. If it is loose or not making a good connection the idiot light will come on and go off or stay on. Also the voltage gauge will jump and sometimes stay at a higher than normal reading.
Last edited by copper; Apr 16, 2007 at 09:55 PM. Reason: punctuation
Thread
Thread Starter
Forum
Replies
Last Post
Kendrick
Pre-Power Stroke Diesel (7.3L IDI & 6.9L)
5
May 12, 2009 09:12 PM
ford03_iw
1999 - 2003 7.3L Power Stroke Diesel
3
Jan 19, 2005 10:44 AM