charging system woes
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Freshman User
Joined: Feb 2005
Posts: 39
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From: kansas
charging system woes
I have read lots of threads about similar problems, and I apologize, but I need help. I am suffering from the dead battery blues. Replaced solenoid, alternator, voltage regulator. Battery dead two days later. Engine running I have 11.7 volts post to post (seems a little low). Not sure where to go from here. Suspect a short somewhere. Any advice welcomed and appreciated. . One thread recommends disconnecting a battery cable putting a test light between the cable and battery, light will be on only if there is a short??
Laughing Gas
Joined: Jan 2002
Posts: 1,008
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From: Tucson
To augment bigretruck's advice, if you have a 12 volt test lamp (probaby 6 or 8 bucks at Autozone) disconnect the negative cable from the battery and connect the test lamp between the disconnected cable and the negative battery terminal. If you have a modern stereo or other electronic device the lamp may glow very dimly. If it glows brighter than that, something is drawing current that should not be.
OOPS, I just re-read your post. you should have 15 or so volts when the engine is running. I'm thinking you have a bad alternator. If you bought it at Autozone or one of the other discount chains, it is a distinct possibility. Let us know.
jor
OOPS, I just re-read your post. you should have 15 or so volts when the engine is running. I'm thinking you have a bad alternator. If you bought it at Autozone or one of the other discount chains, it is a distinct possibility. Let us know.
jor
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Freshman User
Joined: Feb 2005
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From: kansas
After further trouble shooting, the voltage remains about 11v @ 1500rpm, and when you pull the negative cable when running, the truck dies. Also negative cable disconnected w/ multimeter between cable and battery, I show 10.7v static (key off).
Junior User
Joined: Feb 2005
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my 2 cents. If the truck dies when you disconnect the negative post. I would tend to believe that your alternator is not putting out enough voltage. Most of those alt.'s are rebuils and sometimes they are bad from the very start. I had a bad one and had to go through two of the from autozone before I got a good one. Hope this helps
Elder User
Joined: Jan 2003
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From: at my house
I also had two bad altenators, when getting the 3rd from autozone after arguing the fact that my wiring was fine I asked them to check the one they were going to give me before I took it home and you guessed it. It was dead outta the box. I have a good one now, but not to hyjack the post but does anyone out there know of a bolt in quick wiring in higher output alternator?
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Freshman User
Joined: Feb 2005
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From: kansas
took the alternator in and it tested good however the new voltage reg. tested bad. Went to a non discount parts store and purchased a $40 electronic voltage regulator and now the battery alternator appears to be charging but it is only showing about 12.9v (up from 11v). Is this acceptable? My 64 fairlane shows 14.2v while running. I shot the resistance on all 3 alt wires and they are good. Also what voltage should I read on the "I" terminal of the solenoid? Also as a side note I noticed that I had blown a couple fuses in the cab and after replacement my radio and after market tach are inop. They are getting juice though. Could the defective voltage reg. have done this? ? I am beginning to become annoyed. Someone put a vintage air setup, and an F600 inst. panel in this truck and i am begining to question the integrity of the install. . .
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Lead Driver
Joined: Aug 2003
Posts: 7,592
Likes: 10
From: **** hole San Jose ca.
You can check whats coming out of the alternator at large wire on the back of it. or right at the batt. your meter may be a little off so keep that in mind.
12.9 you don't say if your battery is fully charged up good or not. My goes from 12.9 to 13.6 with the newer style regulator and the older type 13.0 to 14.8. I and never had a low battery with the lower voltage charge in 15 yrs. I have a bronco that 12.09 to 13.02 volts and never any low battery troubles
my 2cents
orich
12.9 you don't say if your battery is fully charged up good or not. My goes from 12.9 to 13.6 with the newer style regulator and the older type 13.0 to 14.8. I and never had a low battery with the lower voltage charge in 15 yrs. I have a bronco that 12.09 to 13.02 volts and never any low battery troubles
my 2cents
orich
Lead Driver
Joined: Jan 2005
Posts: 7,782
Likes: 221
From: Huntington Indiana
the more amps an alternator is putting out the lower the voltage to a point. When the battery is fully charges you will have less amps and more volts. try putting a trickle charger overnight on the battery, then check the alt volts and see if it isn't higher.
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Freshman User
Joined: Feb 2005
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From: kansas
Thanks. . The battery was pretty low from all the troubleshooting. What about the fried tach and radio? Have you ever seen a bad voltage regulator do this? It is partially my fault cause I had fuses in place that were a slightly higher amperage than recommended.
Post Fiend
Joined: Jun 2002
Posts: 13,873
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From: Atlanta GA
> when you pull the negative cable when running
A very bad idea to do that. At the very least you will cause a spark near a charging battery venting hydrogen (boom) or at the worse destroy your alternator and voltage regulator.
The most obvious cheap thing is a wire has broken, rusted, or fallen out of the connector to the voltage regulator. On most Ford trucks to guarantee a solid connection I wire tie my connector to the voltage regulator (wrap a loop around both) and then wire tie the wire bundle to the regulator (or radiator support) so the female connectors can not work themselves loose from the connector.
A very bad idea to do that. At the very least you will cause a spark near a charging battery venting hydrogen (boom) or at the worse destroy your alternator and voltage regulator.
The most obvious cheap thing is a wire has broken, rusted, or fallen out of the connector to the voltage regulator. On most Ford trucks to guarantee a solid connection I wire tie my connector to the voltage regulator (wrap a loop around both) and then wire tie the wire bundle to the regulator (or radiator support) so the female connectors can not work themselves loose from the connector.
Lead Driver
Joined: Aug 2003
Posts: 7,592
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From: **** hole San Jose ca.
9 times out of 10 you'll damage something removing the cable when the engine is running. For some reason some guys thing an alternator is a generator And will run with no battery and not damage anything. A alternator
has to have input too get out put.From DC input changed AC volts back to DC. If there's no input voltage theres not going to be any out put voltage and the engine will die in a short time. Some guys in here will arguer this is untrue. But,I say to them remove your battery and try to push start it or remove your cable and try to drive around town with it removed. after about 30 sec or so it dies... my 2cents
orich
has to have input too get out put.From DC input changed AC volts back to DC. If there's no input voltage theres not going to be any out put voltage and the engine will die in a short time. Some guys in here will arguer this is untrue. But,I say to them remove your battery and try to push start it or remove your cable and try to drive around town with it removed. after about 30 sec or so it dies... my 2cents
orich
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Freshman User
Joined: Feb 2005
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From: kansas
Thanks for the input. Seems to be working great now that i bought the good regulator. As a side note though, it ran for almost 30 minutes without the battery hooked up while troubleshooting, then I shut it off. I wont practice this bad habit anymore though. I was always told growing up by the powers that be, that this was how to test a ford alt/regulator. . . .Learn something new every day. .