'93 F-150 - possible alternator problem?

On 02/07/2011 08:32 PM, Tegger wrote:
> > wrote in
> :
>
>
>>
>> The voltage dropoff, at least that I've noticed by watching the dash
>> gauge, does not occur in Park or Neutral because apparently the engine
>> is spinning faster enough that the alt. isn't working as hard...
>>
>
>
>
> Why don't you pull the truck up to a wall, a fat lady, or other solid
> object, then observe the behavior of the headlights from the driver's seat?
>
> Do you even /own/ a VOM? They're very cheap these days, and dead-easy to
> use.
>
>

*sigh*

yes I own a VOM. I'm running myself ragged at work, don't have anything
resembling a workspace, truck is left at work because I don't have
anywhere else to park it (not well lit lot,) and it's been raining
and/or snowing for what seems like weeks. I'm also spending my weekends
putting in 12 hour days trying to get my house ready for sale. Usenet
posts are typically done on "breaks" at work when I'm just too fried to
do anything "useful" without a couple minutes of slacking, and/or when I
can't sleep. So asking questions is quite a bit easier than poking
around with a meter.

I thought my question was pretty straightforward, is it typical for a
standard '93 or thereabouts Ford alternator to noticeably drop off in
voltage at idle with the accessories on? Local mechanics don't seem to
think it's a problem but this is the only alternator-equipped vehicle in
which I've noticed this behavior (save for aforementioned Studebaker,
which doesn't exactly have anything remotely stock on it.) Answer to
that question will determine whether I make a big deal out of it and try
to get alternator warrantied and/or replaced with something better. One
would think with a brand new alternator and battery that I shouldn't be
having any issues at all.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Mon, 07 Feb 2011 20:56:24 -0500, Nate Nagel rearranged some electrons
to say:

> On 02/07/2011 08:32 PM, Tegger wrote:
>> > wrote in
>> :
>>
>>
>>
>>> The voltage dropoff, at least that I've noticed by watching the dash
>>> gauge, does not occur in Park or Neutral because apparently the engine
>>> is spinning faster enough that the alt. isn't working as hard...
>>>
>>>
>>
>>
>> Why don't you pull the truck up to a wall, a fat lady, or other solid
>> object, then observe the behavior of the headlights from the driver's
>> seat?
>>
>> Do you even /own/ a VOM? They're very cheap these days, and dead-easy
>> to use.
>>
>>
>>
> *sigh*
>
> yes I own a VOM. I'm running myself ragged at work, don't have anything
> resembling a workspace, truck is left at work because I don't have
> anywhere else to park it (not well lit lot,) and it's been raining
> and/or snowing for what seems like weeks. I'm also spending my weekends
> putting in 12 hour days trying to get my house ready for sale. Usenet
> posts are typically done on "breaks" at work when I'm just too fried to
> do anything "useful" without a couple minutes of slacking, and/or when I
> can't sleep. So asking questions is quite a bit easier than poking
> around with a meter.
>
> I thought my question was pretty straightforward, is it typical for a
> standard '93 or thereabouts Ford alternator to noticeably drop off in
> voltage at idle with the accessories on? Local mechanics don't seem to
> think it's a problem but this is the only alternator-equipped vehicle in
> which I've noticed this behavior (save for aforementioned Studebaker,
> which doesn't exactly have anything remotely stock on it.) Answer to
> that question will determine whether I make a big deal out of it and try
> to get alternator warrantied and/or replaced with something better. One
> would think with a brand new alternator and battery that I shouldn't be
> having any issues at all.
>
> nate

Your problem could have a multitude of causes. Or, it might not be a
problem at all. Because you are unable to do any basic diagnostic work,
it's difficult to answer your question. Report the charging voltage at
the battery terminals at idle, and also at 2000 RPM or so. As long as
it's above about 13.5 volts, then the alternator is doing a reasonable
job. A voltage drop under load can be caused by a number of things,
corroded terminals, bad wiring, bad switches, etc. Without doing some
troubleshooting, and just shotgunning parts, you're wasting time and
money. Of course, that is your choice.

Nate Nagel > wrote in
:


>
> I thought my question was pretty straightforward, is it typical for a
> standard '93 or thereabouts Ford alternator to noticeably drop off in
> voltage at idle with the accessories on?



Well, this is a Ford, so maybe there are issues I'm unaware of.

But to me, an alternator in good condition should be more than capable of
keeping the system voltage well above 13 even with full-load, and at idle.

Remember that alternators replaced generators for the reason that
generators were often unable to keep up with a loaded system with the
engine at idle.



> Local mechanics don't seem
> to think it's a problem but this is the only alternator-equipped
> vehicle in which I've noticed this behavior (save for aforementioned
> Studebaker, which doesn't exactly have anything remotely stock on it.)
> Answer to that question will determine whether I make a big deal out
> of it and try to get alternator warrantied and/or replaced with
> something better. One would think with a brand new alternator and
> battery that I shouldn't be having any issues at all.
>


True, but my point is that the gauge may be giving you a false indication
of what's actually happening. That's why I'm encouraging you to verify
whether the gauge is fibbing or not.


--
Tegger

Nate Nagel wrote:

> >
>
> *sigh*
>
> yes I own a VOM. I'm running myself ragged at work, don't have anything
> resembling a workspace, truck is left at work because I don't have
> anywhere else to park it (not well lit lot,) and it's been raining
> and/or snowing for what seems like weeks. I'm also spending my weekends
> putting in 12 hour days trying to get my house ready for sale. Usenet
> posts are typically done on "breaks" at work when I'm just too fried to
> do anything "useful" without a couple minutes of slacking, and/or when I
> can't sleep. So asking questions is quite a bit easier than poking
> around with a meter.
>
> I thought my question was pretty straightforward, is it typical for a
> standard '93 or thereabouts Ford alternator to noticeably drop off in
> voltage at idle with the accessories on? Local mechanics don't seem to
> think it's a problem but this is the only alternator-equipped vehicle in
> which I've noticed this behavior (save for aforementioned Studebaker,
> which doesn't exactly have anything remotely stock on it.) Answer to
> that question will determine whether I make a big deal out of it and try
> to get alternator warrantied and/or replaced with something better. One
> would think with a brand new alternator and battery that I shouldn't be
> having any issues at all.

What you are seeing is normal. I wish my 1971 chevy truck's gauge worked
like that. I know that at a slow idle with all the lights and
accessories turned on the voltage does drop a little, but the gauge
needle stays steady as a rock (well maybe with a magnifying glass I
might see it move).

The fact that you don't drive the vehicle very often or for very long
also makes the voltage drop at idle more noticeable because the battery
is sucking more juice than it would if it were charged longer and more
often.

-jim



>
> nate
>
> --
> replace "roosters" with "cox" to reply.
> http://members.cox.net/njnagel

In message >, Tegger
> writes
>Remember that alternators replaced generators for the reason that
>generators were often unable to keep up with a loaded system with the
>engine at idle.
Maybe it's my age, but I can remember alternators replacing generators
because (d.c.) generators didn't produce usable output below 1500rpm.
The were at a much lower gearing due to the much higher centrifugal
effects of the armature, compared to the magnet rotating inside on an
alternator (a.c.) generator.
--
Clive

Clive > wrote:
>Maybe it's my age, but I can remember alternators replacing generators
>because (d.c.) generators didn't produce usable output below 1500rpm.
>The were at a much lower gearing due to the much higher centrifugal
>effects of the armature, compared to the magnet rotating inside on an
>alternator (a.c.) generator.

The regulation on the alternator (even with the old mechanical buzzer
regulators) was much, much better than with the generator. You don't
see headlights dimming when you come to a stop at the intersection the
way you did back then.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On Feb 7, 8:56*pm, Nate Nagel > wrote:
> On 02/07/2011 08:32 PM, Tegger wrote:
>
>
>
>
>
> > > *wrote in
> :
>
> >> The voltage dropoff, at least that I've noticed by watching the dash
> >> gauge, does not occur in Park or Neutral because apparently the engine
> >> is spinning faster enough that the alt. isn't working as hard...
>
> > Why don't you pull the truck up to a wall, a fat lady, or other solid
> > object, then observe the behavior of the headlights from the driver's seat?
>
> > Do you even /own/ a VOM? They're very cheap these days, and dead-easy to
> > use.
>
> *sigh*
>
> yes I own a VOM. *I'm running myself ragged at work, don't have anything
> resembling a workspace, truck is left at work because I don't have
> anywhere else to park it (not well lit lot,) and it's been raining
> and/or snowing for what seems like weeks. *I'm also spending my weekends
> putting in 12 hour days trying to get my house ready for sale. *Usenet
> posts are typically done on "breaks" at work when I'm just too fried to
> do anything "useful" without a couple minutes of slacking, and/or when I
> can't sleep. *So asking questions is quite a bit easier than poking
> around with a meter.
>
> I thought my question was pretty straightforward, is it typical for a
> standard '93 or thereabouts Ford alternator to noticeably drop off in
> voltage at idle with the accessories on? *Local mechanics don't seem to
> think it's a problem but this is the only alternator-equipped vehicle in
> which I've noticed this behavior (save for aforementioned Studebaker,
> which doesn't exactly have anything remotely stock on it.) *Answer to
> that question will determine whether I make a big deal out of it and try
> to get alternator warrantied and/or replaced with something better. *One
> would think with a brand new alternator and battery that I shouldn't be
> having any issues at all.
>
> nate
>
> --
> replace "roosters" with "cox" to reply.http://members.cox.net/njnagel- Hide quoted text -
>
> - Show quoted text -

IMO this isn't that difficult.. If your alternator isn't putting out
enough voltage replace it. If your battery is 4-5 years old replace
that too. Of course checking for any corrosion on the alternator &
battery might help too before replacing any components.

On Feb 8, 2:39*pm, m6onz5a > wrote:
> On Feb 7, 8:56*pm, Nate Nagel > wrote:
>
>
>
>
>
> > On 02/07/2011 08:32 PM, Tegger wrote:
>
> > > > *wrote in
> > :
>
> > >> The voltage dropoff, at least that I've noticed by watching the dash
> > >> gauge, does not occur in Park or Neutral because apparently the engine
> > >> is spinning faster enough that the alt. isn't working as hard...
>
> > > Why don't you pull the truck up to a wall, a fat lady, or other solid
> > > object, then observe the behavior of the headlights from the driver's seat?
>
> > > Do you even /own/ a VOM? They're very cheap these days, and dead-easy to
> > > use.
>
> > *sigh*
>
> > yes I own a VOM. *I'm running myself ragged at work, don't have anything
> > resembling a workspace, truck is left at work because I don't have
> > anywhere else to park it (not well lit lot,) and it's been raining
> > and/or snowing for what seems like weeks. *I'm also spending my weekends
> > putting in 12 hour days trying to get my house ready for sale. *Usenet
> > posts are typically done on "breaks" at work when I'm just too fried to
> > do anything "useful" without a couple minutes of slacking, and/or when I
> > can't sleep. *So asking questions is quite a bit easier than poking
> > around with a meter.
>
> > I thought my question was pretty straightforward, is it typical for a
> > standard '93 or thereabouts Ford alternator to noticeably drop off in
> > voltage at idle with the accessories on? *Local mechanics don't seem to
> > think it's a problem but this is the only alternator-equipped vehicle in
> > which I've noticed this behavior (save for aforementioned Studebaker,
> > which doesn't exactly have anything remotely stock on it.) *Answer to
> > that question will determine whether I make a big deal out of it and try
> > to get alternator warrantied and/or replaced with something better. *One
> > would think with a brand new alternator and battery that I shouldn't be
> > having any issues at all.
>
> > nate
>
> > --
> > replace "roosters" with "cox" to reply.http://members.cox.net/njnagel-Hide quoted text -
>
> > - Show quoted text -
>
> IMO this isn't that difficult.. If your alternator isn't putting out
> enough voltage replace it. If your battery is 4-5 years old replace
> that too. Of course checking for any corrosion on the alternator &
> battery might help too before replacing any components.

That's the problem, all of that has already been done, and recently
too.

nate

Nate Nagel wrote:

>
> yes I own a VOM. I'm running myself ragged at work, don't have anything
> resembling a workspace, truck is left at work because I don't have
> anywhere else to park it (not well lit lot,) and it's been raining
> and/or snowing for what seems like weeks. I'm also spending my weekends
> putting in 12 hour days trying to get my house ready for sale. Usenet
> posts are typically done on "breaks" at work when I'm just too fried to
> do anything "useful" without a couple minutes of slacking, and/or when I
> can't sleep. So asking questions is quite a bit easier than poking
> around with a meter.
>
> I thought my question was pretty straightforward, is it typical for a
> standard '93 or thereabouts Ford alternator to noticeably drop off in
> voltage at idle with the accessories on? Local mechanics don't seem to
> think it's a problem but this is the only alternator-equipped vehicle in
> which I've noticed this behavior (save for aforementioned Studebaker,
> which doesn't exactly have anything remotely stock on it.) Answer to
> that question will determine whether I make a big deal out of it and try
> to get alternator warrantied and/or replaced with something better. One
> would think with a brand new alternator and battery that I shouldn't be
> having any issues at all.
>
> nate
>

Haven't been paying attention but if the problem is that in cold weather
with all accessories on you're seeing enough of a drop to dim the lights
noticeably then you have a problem. The reason being that in cold
weather the voltage should actually ramp up some to cover the drain
caused by the accessories and the cold. Temperature compensated
regulators do that by design.

--
Steve W.
(\___/)
(='.'=)
(")_(")

On Feb 8, 2:45*pm, N8N > wrote:
> On Feb 8, 2:39*pm, m6onz5a > wrote:
>
>
>
>
>
> > On Feb 7, 8:56*pm, Nate Nagel > wrote:
>
> > > On 02/07/2011 08:32 PM, Tegger wrote:
>
> > > > > *wrote in
> > > :
>
> > > >> The voltage dropoff, at least that I've noticed by watching the dash
> > > >> gauge, does not occur in Park or Neutral because apparently the engine
> > > >> is spinning faster enough that the alt. isn't working as hard...
>
> > > > Why don't you pull the truck up to a wall, a fat lady, or other solid
> > > > object, then observe the behavior of the headlights from the driver's seat?
>
> > > > Do you even /own/ a VOM? They're very cheap these days, and dead-easy to
> > > > use.
>
> > > *sigh*
>
> > > yes I own a VOM. *I'm running myself ragged at work, don't have anything
> > > resembling a workspace, truck is left at work because I don't have
> > > anywhere else to park it (not well lit lot,) and it's been raining
> > > and/or snowing for what seems like weeks. *I'm also spending my weekends
> > > putting in 12 hour days trying to get my house ready for sale. *Usenet
> > > posts are typically done on "breaks" at work when I'm just too fried to
> > > do anything "useful" without a couple minutes of slacking, and/or when I
> > > can't sleep. *So asking questions is quite a bit easier than poking
> > > around with a meter.
>
> > > I thought my question was pretty straightforward, is it typical for a
> > > standard '93 or thereabouts Ford alternator to noticeably drop off in
> > > voltage at idle with the accessories on? *Local mechanics don't seem to
> > > think it's a problem but this is the only alternator-equipped vehicle in
> > > which I've noticed this behavior (save for aforementioned Studebaker,
> > > which doesn't exactly have anything remotely stock on it.) *Answer to
> > > that question will determine whether I make a big deal out of it and try
> > > to get alternator warrantied and/or replaced with something better. *One
> > > would think with a brand new alternator and battery that I shouldn't be
> > > having any issues at all.
>
> > > nate
>
> > > --
> > > replace "roosters" with "cox" to reply.http://members.cox.net/njnagel-Hidequoted text -
>
> > > - Show quoted text -
>
> > IMO this isn't that difficult.. If your alternator isn't putting out
> > enough voltage replace it. If your battery is 4-5 years old replace
> > that too. Of course checking for any corrosion on the alternator &
> > battery might help too before replacing any components.
>
> That's the problem, all of that has already been done, and recently
> too.
>
> nate- Hide quoted text -
>
> - Show quoted text -

It is possible you have a defective part. Fully charge the battery
and give it a load test. Also give us a reading on what the
alternater is charging at idle. Check for any loose/dirty connections
and check to see if the belt might be slipping.

Chas