'93 F-150 - possible alternator problem?

Nate Nagel wrote:
> hi all
>
> had alt. replaced in '93 F-150 a while back... stopped charging on way
> home from work one day. just more recently I noticed slow starting when
> cold so had battery replaced. Today I had to drive the truck in a cold
> rain so I had lights, wipers, defrost, etc. on. At idle in gear volt
> gauge would drop to about "O" in "NORMAL" where it usually sits between
> "M" and "A" (sorry, no voltage readings - didn't have meter with me.)
> Should I be worried, or is this normal? I have to say I don't
> particularly like it, as stop and go traffic is not particularly
> uncommon around here (DC-land.) If it's NOT normal, where can I get a
> GOOD alternator?
>
> thanks
>
> nate
>
I read all the replies, here is all you need. Stick in the cigarette
lighter and you can determine if the alternator is doing it's job, the
charge of the battery and after using it a while know get a good feeling
of what's doing what. One of the handiest things to have around I know
of when there are charging/battery/starting problems.

http://www.amazon.com/Peak-PKC0AP-Ba...7252307&sr=8-7

On Tue, 8 Feb 2011 19:12:48 +0000, Clive >
wrote:

>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.

IMHO both of you are correct. Generators were somewhat current
challenged (for a generator to produce 75 amps would require some
massive brushes, and other components), and as well generators didn't
produce good current at anything less that cruising speeds, and could
not be geared up because then they'd self destruct at high engine
RPMs.

On 02/05/2011 02:17 PM, Nate Nagel wrote:
> hi all
>
> had alt. replaced in '93 F-150 a while back... stopped charging on way
> home from work one day. just more recently I noticed slow starting when
> cold so had battery replaced. Today I had to drive the truck in a cold
> rain so I had lights, wipers, defrost, etc. on. At idle in gear volt
> gauge would drop to about "O" in "NORMAL" where it usually sits between
> "M" and "A" (sorry, no voltage readings - didn't have meter with me.)
> Should I be worried, or is this normal? I have to say I don't
> particularly like it, as stop and go traffic is not particularly
> uncommon around here (DC-land.) If it's NOT normal, where can I get a
> GOOD alternator?
>
> thanks
>
> nate
>
I own a 1993 F-150, straight 6, 4.9L engine, 5 speed Toyo-Kogyo Mazda
transmission. Battery is from 9/2008. Mileage is 118,174.

Running heater, lights, wipers, radio, in rain at 40 degrees F, the
alternator seemed to sag in power, the other morning. the meter dropped
to the bottom of the "Normal" range.

I think the belt slipped after going through a large puddle of water.

Automotive charging systems are dynamic in their operation, meaning that
the conditions and outputs are variable, due to outside factors.

This alternator is quite satisfactory at most operational conditions,
but, there will be times when the "envelope" of normal performance is
exceeded.

I do clean both ends of all the battery cables, each year. I am in
Central Florida. In Northern states, where salt is used, I would
do this cleaning twice each year.

If the engine or battery ground (Negative) cables get a bit of
corrosion, then the voltage can really take a dump!

I would clean the battery terminals, and check the positive cable at the
engine solenoid on the inner fender. Check the negative cable on both
ends. All my cables were all new, with the battery, in 2008, and the
negative cable connects under my upper starter bolt.

But, what could I know, at 64, as a retired Air Force electronics
technician on exotic aircraft which I still can't tell you about,
because I'm sworn to secrecy, and, it would break national security.

On Thu, 10 Feb 2011 07:37:28 -0500, Big Red Truck >
wrote:

>On 02/05/2011 02:17 PM, Nate Nagel wrote:
>> hi all
>>
>> had alt. replaced in '93 F-150 a while back... stopped charging on way
>> home from work one day. just more recently I noticed slow starting when
>> cold so had battery replaced. Today I had to drive the truck in a cold
>> rain so I had lights, wipers, defrost, etc. on. At idle in gear volt
>> gauge would drop to about "O" in "NORMAL" where it usually sits between
>> "M" and "A" (sorry, no voltage readings - didn't have meter with me.)
>> Should I be worried, or is this normal? I have to say I don't
>> particularly like it, as stop and go traffic is not particularly
>> uncommon around here (DC-land.) If it's NOT normal, where can I get a
>> GOOD alternator?
>>
>> thanks
>>
>> nate
>>
>I own a 1993 F-150, straight 6, 4.9L engine, 5 speed Toyo-Kogyo Mazda
>transmission. Battery is from 9/2008. Mileage is 118,174.
>
>Running heater, lights, wipers, radio, in rain at 40 degrees F, the
>alternator seemed to sag in power, the other morning. the meter dropped
>to the bottom of the "Normal" range.
>
>I think the belt slipped after going through a large puddle of water.
>
>Automotive charging systems are dynamic in their operation, meaning that
>the conditions and outputs are variable, due to outside factors.
>
>This alternator is quite satisfactory at most operational conditions,
>but, there will be times when the "envelope" of normal performance is
>exceeded.
>
>I do clean both ends of all the battery cables, each year. I am in
>Central Florida. In Northern states, where salt is used, I would
>do this cleaning twice each year.
>
>If the engine or battery ground (Negative) cables get a bit of
>corrosion, then the voltage can really take a dump!
>
>I would clean the battery terminals, and check the positive cable at the
>engine solenoid on the inner fender. Check the negative cable on both
>ends. All my cables were all new, with the battery, in 2008, and the
>negative cable connects under my upper starter bolt.
>
>But, what could I know, at 64, as a retired Air Force electronics
>technician on exotic aircraft which I still can't tell you about,
>because I'm sworn to secrecy, and, it would break national security.

WTF, a retired AF mechanic trying to use a vehicle's dash volt meter?
Throw a real meter (VOM or a DVOM) on it and see what's really
happening.

PeterD wrote:

> WTF, a retired AF mechanic trying to use a vehicle's dash volt meter?
> Throw a real meter (VOM or a DVOM) on it and see what's really
> happening.

Well sure if your a duck you get out and splash around in the driving
rain every time your truck runs through a puddle of water.

On 02/10/2011 07:37 AM, Big Red Truck wrote:
> On 02/05/2011 02:17 PM, Nate Nagel wrote:
>> hi all
>>
>> had alt. replaced in '93 F-150 a while back... stopped charging on way
>> home from work one day. just more recently I noticed slow starting when
>> cold so had battery replaced. Today I had to drive the truck in a cold
>> rain so I had lights, wipers, defrost, etc. on. At idle in gear volt
>> gauge would drop to about "O" in "NORMAL" where it usually sits between
>> "M" and "A" (sorry, no voltage readings - didn't have meter with me.)
>> Should I be worried, or is this normal? I have to say I don't
>> particularly like it, as stop and go traffic is not particularly
>> uncommon around here (DC-land.) If it's NOT normal, where can I get a
>> GOOD alternator?
>>
>> thanks
>>
>> nate
>>
> I own a 1993 F-150, straight 6, 4.9L engine, 5 speed Toyo-Kogyo Mazda
> transmission. Battery is from 9/2008. Mileage is 118,174.
>
> Running heater, lights, wipers, radio, in rain at 40 degrees F, the
> alternator seemed to sag in power, the other morning. the meter dropped
> to the bottom of the "Normal" range.
>
> I think the belt slipped after going through a large puddle of water.
>
> Automotive charging systems are dynamic in their operation, meaning that
> the conditions and outputs are variable, due to outside factors.
>
> This alternator is quite satisfactory at most operational conditions,
> but, there will be times when the "envelope" of normal performance is
> exceeded.
>
> I do clean both ends of all the battery cables, each year. I am in
> Central Florida. In Northern states, where salt is used, I would
> do this cleaning twice each year.
>
> If the engine or battery ground (Negative) cables get a bit of
> corrosion, then the voltage can really take a dump!
>
> I would clean the battery terminals, and check the positive cable at the
> engine solenoid on the inner fender. Check the negative cable on both
> ends. All my cables were all new, with the battery, in 2008, and the
> negative cable connects under my upper starter bolt.
>
> But, what could I know, at 64, as a retired Air Force electronics
> technician on exotic aircraft which I still can't tell you about,
> because I'm sworn to secrecy, and, it would break national security.
>
Forgot to mention, it bounced back in about 30 seconds, so, it was
probably belt slip due to the splash of water.

I own a whole shelf of digital VOMs, and a couple cigarette lighter
led testors, that are super cheap, from Harbor Freight Tools.

If you have corrosion on a cable end, and it results in one ohm of
resistance, then, at 13.8 Volts DC you would lose 13.8 Amps of current
just at that one dirty connection!

The 1993 F-150 XL, 4.9L engine, have 65 Amp alternators. Not much
capacity left after the needs of the lights, heater fan, wipers, to
waste on bad connections!

No matter that you can replace it with a 100 amp alternator by Bosch,
for only $112, still need clean connections on all wiring!

In message m>, Big Red
Truck > writes
>If you have corrosion on a cable end, and it results in one ohm of
>resistance, then, at 13.8 Volts DC you would lose 13.8 Amps of current
>just at that one dirty connection!
I read what you said you know, but this sentence gives me serious reason
to doubt you.
--
Clive