Alternator Problem?
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Alternator Problem?
Battery light on dash started flashing this morning. No problem starting. Turned off and checked battery voltage. 12.9 volts. Started truck and checked. 12.5 volts. Sounds like alternator went bad?
How do you take the wires off of it? One looks like a plug, the other something else. They can be rebuilt right, new voltage regulator and such.
Going to charge batteries now to keep them good.
Thanks.....
2002 F-350 Dually CC
How do you take the wires off of it? One looks like a plug, the other something else. They can be rebuilt right, new voltage regulator and such.
Going to charge batteries now to keep them good.
Thanks.....
2002 F-350 Dually CC
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FTE-Spread The Knowledge
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Thanks. After a while it did go to 14.2 and stayed. Both batteries are at 13.5 and 13.6, disconnected from truck.
I wonder what is up with the battery light. It flickers sometimes and goes out, or stays on for a while and goes out?
I wonder what is up with the battery light. It flickers sometimes and goes out, or stays on for a while and goes out?
Cargo Master
Joined: Jun 2003
Posts: 3,292
Likes: 6
From: Ardenvoir, Washington
Check your alternator wiring for shorts.. or a dirty or loose connector on top.. Another area to check is the main wire bundle that goes over the top of the driver's side valve cover...this bundle can rub on the cover over time.. Mine battery light was flickering awhile back and it was one of the small wires that come the top of the alternator was shorting out on the aluminium housing, just down from the wire connector..
Posting Guru
Joined: Jul 2004
Posts: 1,777
Likes: 0
From: Buckingham, IA
It still could be your alternator. Could have problems when it warms up. Check the voltage when the alt. is warm and, if possible, when the light is flickering. Otherwise, you are checking out fine.
Lead Driver
Joined: Jan 2007
Posts: 6,708
Likes: 5
From: Kiowa CO
My Battery flashed for a quick trip to my son's football game and on the return trip, stayed on all the way home. IIRC, my volts were reading the same as yours and it ended up being the alternator. It's super-simple to swap out - loosen the belt, unhook the wire harness, three bolts hold it down and install the new unit.
On edit: my volts didn't go back to 14 though, on my aftermarket voltmeter it read no higher than 13v on the road at speed and around 12.5v at idle at stoplights.
On edit: my volts didn't go back to 14 though, on my aftermarket voltmeter it read no higher than 13v on the road at speed and around 12.5v at idle at stoplights.
Freshman User
Joined: May 2007
Posts: 47
Likes: 0
From: Gray, TN
Take it to an autozone etc and they can test the alternator on the car. Luckily my buddy works at one and month after putting 2 new 1000 CCA batteries on it was still hard to start. Turns out the diode in the alt was bad and leaking juice out slowly. The alternator can be rebuilt, but I found it easier to just get one at the parts store with a lifetime warranty.
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Cargo Master
Joined: Mar 2006
Posts: 2,502
Likes: 2
From: Bend Oregon
be careful with the parts store testers, I lost an alternator about a year ago, purchased a lifetime replacement from NAPA threw it in and everything seemed fine....until it got dark. Tested it with my fluke 87 DVM and it was fluctuating from 13.3vdc to 16.2vdc causing my light to flicker very noticeably. I removed the alternator and attempted to exchange it was told it tests good and then was convinced that it must be a bad battery
$250 later for two new interstate batteries my lights where still flickering…once again attempted to return alternator was told it was fine. I ended up having to call the owner of the NAPA and bring in my DVM to prove that the alternator was bad as well as the other 4 they had on the shelf. I think the reman faculity had a bad run of rectifiers and was only chopping 1 side of the voltage off. <o
></o>
<o> </o>
Long story short….part store testers are not fast enough to pick up if the voltage is being rectified properly only if there is enough voltage present. <o></o>
$250 later for two new interstate batteries my lights where still flickering…once again attempted to return alternator was told it was fine. I ended up having to call the owner of the NAPA and bring in my DVM to prove that the alternator was bad as well as the other 4 they had on the shelf. I think the reman faculity had a bad run of rectifiers and was only chopping 1 side of the voltage off. <o
></o><o
> </o>Long story short….part store testers are not fast enough to pick up if the voltage is being rectified properly only if there is enough voltage present. <o
></o>
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Thanks. Just getting all the stuff ready to change out the water pump and the battery light starts up. Luckily the water pump is just dripping giving me time to get everything together. I am keeping a very close eye on it.
I am going to check the wires today. I talked to our local alternator rebuild guy. Vety nice. He said he will do it up right, and he has always backed his work with us. It takes an hour and costs $100. The big wire on the back unbolts and the other is a plug right? They both are very secure now. Is there a fix so that the wire harness doesn't settle on the VC? I always check it because you read so much about it, but often wondered if anyone has improved it someway? The light stayed off after I took the batteries out cleaned charged and returned. Put some NAPA battry clean on. Had a very small amount of buildup. Kinda hoping it will flicker this morning so I can check it then.... that is a good idea, thanks.
Back to the water pump, what is a good product to put on the water pump bolts to keep them easy to remove for the next time I have a problem? Also, taking off the fan nut, facing it I will turn to the right correct?
I am going to check the wires today. I talked to our local alternator rebuild guy. Vety nice. He said he will do it up right, and he has always backed his work with us. It takes an hour and costs $100. The big wire on the back unbolts and the other is a plug right? They both are very secure now. Is there a fix so that the wire harness doesn't settle on the VC? I always check it because you read so much about it, but often wondered if anyone has improved it someway? The light stayed off after I took the batteries out cleaned charged and returned. Put some NAPA battry clean on. Had a very small amount of buildup. Kinda hoping it will flicker this morning so I can check it then.... that is a good idea, thanks.
Back to the water pump, what is a good product to put on the water pump bolts to keep them easy to remove for the next time I have a problem? Also, taking off the fan nut, facing it I will turn to the right correct?
Lead Driver
Joined: Jan 2007
Posts: 6,708
Likes: 5
From: Kiowa CO
Thanks. Just getting all the stuff ready to change out the water pump and the battery light starts up. Luckily the water pump is just dripping giving me time to get everything together. I am keeping a very close eye on it.
I am going to check the wires today. I talked to our local alternator rebuild guy. Vety nice. He said he will do it up right, and he has always backed his work with us. It takes an hour and costs $100. The big wire on the back unbolts and the other is a plug right? They both are very secure now. Is there a fix so that the wire harness doesn't settle on the VC? I always check it because you read so much about it, but often wondered if anyone has improved it someway? The light stayed off after I took the batteries out cleaned charged and returned. Put some NAPA battry clean on. Had a very small amount of buildup. Kinda hoping it will flicker this morning so I can check it then.... that is a good idea, thanks.
Back to the water pump, what is a good product to put on the water pump bolts to keep them easy to remove for the next time I have a problem? Also, taking off the fan nut, facing it I will turn to the right correct?
I am going to check the wires today. I talked to our local alternator rebuild guy. Vety nice. He said he will do it up right, and he has always backed his work with us. It takes an hour and costs $100. The big wire on the back unbolts and the other is a plug right? They both are very secure now. Is there a fix so that the wire harness doesn't settle on the VC? I always check it because you read so much about it, but often wondered if anyone has improved it someway? The light stayed off after I took the batteries out cleaned charged and returned. Put some NAPA battry clean on. Had a very small amount of buildup. Kinda hoping it will flicker this morning so I can check it then.... that is a good idea, thanks.
Back to the water pump, what is a good product to put on the water pump bolts to keep them easy to remove for the next time I have a problem? Also, taking off the fan nut, facing it I will turn to the right correct?
If the wire is close to the bracket and looks to rub on it, get a piece of the split plastic wire loom and slip it over the harness and fasten with a zip tie.
I never replaced a WP on this truck (yet) but you can use Anti-seize on the bolts (found in the RTV section at AutoZoo) and the fan nut is threaded like any other nut. Read step #11 of these instructions. Water Pump Replacement
Mountain Pass
Joined: Sep 2009
Posts: 132
Likes: 6
From: illinois
I agree w/ Clem, alot of bad alternators sit on shelves, not sure about the rectifier part, but I know the Diods can be bad and make the alternator do what you described, Cause it's doing it now in my '01 P71, and the P71 I had before was doing crazy things, meter in car was like all over the place, bouncing like mad! Ha! think it was a diod then.
FTrucker
FTrucker
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Yes, unbolt the wire and the undo the plug. Cavemen can do it.
If the wire is close to the bracket and looks to rub on it, get a piece of the split plastic wire loom and slip it over the harness and fasten with a zip tie.
I never replaced a WP on this truck (yet) but you can use Anti-seize on the bolts (found in the RTV section at AutoZoo) and the fan nut is threaded like any other nut. Read step #11 of these instructions. Water Pump Replacement
If the wire is close to the bracket and looks to rub on it, get a piece of the split plastic wire loom and slip it over the harness and fasten with a zip tie.
I never replaced a WP on this truck (yet) but you can use Anti-seize on the bolts (found in the RTV section at AutoZoo) and the fan nut is threaded like any other nut. Read step #11 of these instructions. Water Pump Replacement
Cargo Master
Joined: Jun 2003
Posts: 3,292
Likes: 6
From: Ardenvoir, Washington
In the "Water Pump Replacement" link above... it states:
Remove the fan and fan clutch from the water-pump pulley. The large clutch assembly has a right-hand thread and must be turned counter-clockwise in order to remove it. Hold on to the belt pulley with the strap wrench, and use a 1-7/8 inch open-end wrench to break the fan free. Once removed from the pulley, carefully lay the fan down into the shroud temporarily.
Remove the fan and fan clutch from the water-pump pulley. The large clutch assembly has a right-hand thread and must be turned counter-clockwise in order to remove it. Hold on to the belt pulley with the strap wrench, and use a 1-7/8 inch open-end wrench to break the fan free. Once removed from the pulley, carefully lay the fan down into the shroud temporarily.
Cargo Master
Joined: Mar 2006
Posts: 2,502
Likes: 2
From: Bend Oregon
water pump is not that big of a deal, I have done it twice on my truck. My personal preference is to remove the radiator; then you can get the shroud out before you remove the fan/fan clutch. Upon re install I did coat the water pump pulley threads with never seize due to the fact it is aluminum on steel.
My first water pump r&r I ended up cutting the fan clutch off the pulley (dang they are expensive) but on the second r&r 170,000 miles later the fan clutch came off like it is supposed too.
autozone rents a tool to remove the fan clutch that works pretty slick and there are a few members on here that have made their own.
all in all it is a lot easier than it looks and took me maybe me maybe 3 hours with a coolant filter install thrown in and a break to help my brother in law get his dirtbike running.
My first water pump r&r I ended up cutting the fan clutch off the pulley (dang they are expensive) but on the second r&r 170,000 miles later the fan clutch came off like it is supposed too.
autozone rents a tool to remove the fan clutch that works pretty slick and there are a few members on here that have made their own.
all in all it is a lot easier than it looks and took me maybe me maybe 3 hours with a coolant filter install thrown in and a break to help my brother in law get his dirtbike running.
Hotshot
Joined: Jan 2002
Posts: 17,988
Likes: 207
From: La La Land
That's what rectifies, the diodes.
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