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alternator problems maybe?

Bloodhound

Bloodhound

Oilfield Trash
835
47
Crowville Louisiana
I have had a problem with my batteries going down over time. i am thinking that it is my alternator. I teste it with a Black and decker smart charger. It says that it is out of range. What should it read if I test it at the alt with a volt meter? Mine read 12.4 volts while running.

Could I have it rebuilt a a high output alt? If not wher can I get the highest output alt?

Thanks guys.
 
SuperCab

SuperCab

Moderator
Staff member
10,068
547
Montana
AFAIK it should be 13.5 - 15 volts when running.

12.4 would seem to indicate a problem with you're charging system.

IDK all the inner workings of an '04 but it's not necesarily the alt. Just something to think about...
 
TexasNomad

TexasNomad

FTFS Designated DRINKER!
17,057
676
Half past hell AKA Lubbock Tx
Yeah that's way to low there boss man.
 

bowtiehatr

Certified Ford Tech
859
21
Florence, South Carolina
when did you check the voltage? upon startup, the glow plugs can be on for up to two minutes. when they are on, the alternator will not charge.
 
d-kuzmen

d-kuzmen

Master Ford Tech
2,109
79
Connecticut
I ususally like to see anywhere between 13 to 14 volts, I also will turn the headlights on when checking just to see if it can take the load, I also bring it up off idle because they don't always put out there full voltage while idleing.
 

bowtiehatr

Certified Ford Tech
859
21
Florence, South Carolina
at startup it will read whatever batteries are at 12.somethingV. let the truck run for a few minutes before checking voltage.
 
Skandocious

Skandocious

Post Whores Make Me Sick
19,076
655
California
bowtiehatr said:
at startup it will read whatever batteries are at 12.somethingV. let the truck run for a few minutes before checking voltage.
Click to expand...
smiliewhathesaid Those glowplugs pull a surprising amount of power for a little while after startup. Take it for a short drive then come home and leave it running while you check the voltage at the alt again. And like Dave said-- if you've got an idle controller it might be good to idle it up a bit while testing-- at idle, an alternator puts out a very little amount of power compared to it's maximum output.


graph.gif


Junior said:
Bad voltage regulator maybe.....still gotta replace the altenator....the VR is internal.
Click to expand...
Hm? Rockauto has a Motorcraft 6.0L voltage regulator for $60. Looks to me like it's serviceable..


gr815.jpg
 
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