Help Needed for 93 Ford F150 XLT Electrical Problem

On Fri, 10 Oct 2008 03:22:40 -0500, arehm <none DeleteThis @000.com> wrote:

>Hi, can anybody help give me a clue on what might be the
>problem with my 93 F150. The alternator drains the battery,
>and it’s new and have taken it back to Pep Boys and had it
>retested and it passes ok. The battery is new also.
>
>When I start up my truck after it’s been sitting for a few hrs
>or a day the battery gauge in the dash reads normal in the
>middle, but after idling for a few minutes the gauge needle
>drops down then starts to drain the battery.
>
>The alternator does get hot, but I don’t see any
>problems with the wire harness or connectors melting or
>shorting anywhere. I have replaced the relay mounted on
>the inside fender wall near the battery, but still get the
>same results.
>
>Anybody have any knowledge? Thanks


If I understand correctly, it drains the battery when idling. This is a common
symptom of a failed IAC (idle air control) which is not maintaining proper
engine idle speed. The alter will cut out completely when the engine drops
below a minimum speed. This means everything that draws power is still working
with no alternater support. Make sure the IAC is maintaining proper idle. You
should probabl remove and clean the throtttle body at the same time. I know it
has/had a sticker saying not to clean it but, trust me, they still get dirty and
choked. If this doesn't do it, have a diagnostic scan for stored fault codes
done. They are usually a free service at many parts stores on the hope you will
buy their parts. You should not just buy parts. Post the code along with any
display definitions. Someone here will probably be able to help you interpret
any fault codes.


Lugnut
 >> Stay informed about: Help Needed for 93 Ford F150 XLT Electrical Problem 

"lugnut" <lugnut DeleteThis @roadkill.net> wrote in message
news:gtkue4pfqn2up94djq3kblvvd9am98gpui@4ax.com...
> On Fri, 10 Oct 2008 03:22:40 -0500, arehm <none DeleteThis @000.com> wrote:
>
>>Hi, can anybody help give me a clue on what might be the
>>problem with my 93 F150. The alternator drains the battery,
>>and it's new and have taken it back to Pep Boys and had it
>>retested and it passes ok. The battery is new also.
>>
>>When I start up my truck after it's been sitting for a few hrs
>>or a day the battery gauge in the dash reads normal in the
>>middle, but after idling for a few minutes the gauge needle
>>drops down then starts to drain the battery.
>>
>>The alternator does get hot, but I don't see any
>>problems with the wire harness or connectors melting or
>>shorting anywhere. I have replaced the relay mounted on
>>the inside fender wall near the battery, but still get the
>>same results.
>>
>>Anybody have any knowledge? Thanks
>
>
> If I understand correctly, it drains the battery when idling. This is a
> common
> symptom of a failed IAC (idle air control) which is not maintaining proper
> engine idle speed. The alter will cut out completely when the engine
> drops
> below a minimum speed. This means everything that draws power is still
> working
> with no alternater support. Make sure the IAC is maintaining proper idle.
> You
> should probabl remove and clean the throtttle body at the same time. I
> know it
> has/had a sticker saying not to clean it but, trust me, they still get
> dirty and
> choked. If this doesn't do it, have a diagnostic scan for stored fault
> codes
> done. They are usually a free service at many parts stores on the hope
> you will
> buy their parts. You should not just buy parts. Post the code along with
> any
> display definitions. Someone here will probably be able to help you
> interpret
> any fault codes.
>
>
> Lugnut

I'm not so sure the IAC could be the culprit- I've had a few go bad on me,
and the vehicle wouldn't idle at all unless I gave it the throttle myself.
There was no way I could walk away and let it idle- it would be stopped
before I opened the door if I tried. Still can't hurt to clean it and the TB
while he's troubleshooting, though.
That said, it could be some accessory dragging it down, like a direct wired
radio or amp, or a bad ground from engine to chassis, or a bare wire. Or it
could be the voltage regulator. If you know someone with a DC ammeter, you
can test for drain with the engine off, at idle, and at high RPM.
You might want to have your battery tested- even though it's new, it can be
bad.

SC Tom
 >> Stay informed about: Help Needed for 93 Ford F150 XLT Electrical Problem 

"arehm" <none.TakeThisOut@000.com> wrote in message
news:1126662_b79f74a62008eb3e76e27a2ae1e57ed5@autoforumz.com...
> Hi, can anybody help give me a clue on what might be the
> problem with my 93 F150. The alternator drains the battery,
> and it's new and have taken it back to Pep Boys and had it
> retested and it passes ok. The battery is new also.
>
> When I start up my truck after it's been sitting for a few hrs
> or a day the battery gauge in the dash reads normal in the
> middle, but after idling for a few minutes the gauge needle
> drops down then starts to drain the battery.
>
> The alternator does get hot, but I don't see any
> problems with the wire harness or connectors melting or
> shorting anywhere. I have replaced the relay mounted on
> the inside fender wall near the battery, but still get the
> same results.
>
> Anybody have any knowledge? Thanks
>
> --

93's have a serpentine belt, so it should not be slipping. You say after a
few minutes this happens. Here is what I would do to start. Disconnect all
the wires from the alternator. Make sure none of them can come in contact
with something else. Start the engine, note the "battery gauge" and see what
it does. Make sure all the accessories and AC are off. Let us know what
happens.

When Pep Boys checked the alternator, did they do it on the truck or did you
remove it?

Al
 >> Stay informed about: Help Needed for 93 Ford F150 XLT Electrical Problem 

"lugnut" <lugnut.DeleteThis@roadkill.net> wrote in message
news:gtkue4pfqn2up94djq3kblvvd9am98gpui@4ax.com...
> On Fri, 10 Oct 2008 03:22:40 -0500, arehm <none.DeleteThis@000.com> wrote:
>
>>Hi, can anybody help give me a clue on what might be the
>>problem with my 93 F150. The alternator drains the battery,
>>and it's new and have taken it back to Pep Boys and had it
>>retested and it passes ok. The battery is new also.
>>
>>When I start up my truck after it's been sitting for a few hrs
>>or a day the battery gauge in the dash reads normal in the
>>middle, but after idling for a few minutes the gauge needle
>>drops down then starts to drain the battery.
>>
>>The alternator does get hot, but I don't see any
>>problems with the wire harness or connectors melting or
>>shorting anywhere. I have replaced the relay mounted on
>>the inside fender wall near the battery, but still get the
>>same results.
>>
>>Anybody have any knowledge? Thanks
>
>
> If I understand correctly, it drains the battery when idling. This is a
> common
> symptom of a failed IAC (idle air control) which is not maintaining proper
> engine idle speed. The alter will cut out completely when the engine
> drops
> below a minimum speed. This means everything that draws power is still
> working
> with no alternater support. Make sure the IAC is maintaining proper idle.
> You
> should probabl remove and clean the throtttle body at the same time. I
> know it
> has/had a sticker saying not to clean it but, trust me, they still get
> dirty and
> choked. If this doesn't do it, have a diagnostic scan for stored fault
> codes
> done. They are usually a free service at many parts stores on the hope
> you will
> buy their parts. You should not just buy parts. Post the code along with
> any
> display definitions. Someone here will probably be able to help you
> interpret
> any fault codes.
>
>
> Lugnut

I'm not so sure the IAC could be the culprit- I've had a few go bad on me,
and the vehicle wouldn't idle at all unless I gave it the throttle myself.
There was no way I could walk away and let it idle- it would be stopped
before I opened the door if I tried. Still can't hurt to clean it and the TB
while he's troubleshooting, though.
That said, it could be some accessory dragging it down, like a direct wired
radio or amp, or a bad ground from engine to chassis, or a bare wire. Or it
could be the voltage regulator. If you know someone with a DC ammeter, you
can test for drain with the engine off, at idle, and at high RPM.
You might want to have your battery tested- even though it's new, it can be
bad.

SC Tom
 >> Stay informed about: Help Needed for 93 Ford F150 XLT Electrical Problem 

On Fri, 10 Oct 2008 11:03:08 -0400, "SC Tom" <sc.RemoveThis@tom.net> wrote:

>
>"lugnut" <lugnut.RemoveThis@roadkill.net> wrote in message
>news:gtkue4pfqn2up94djq3kblvvd9am98gpui@4ax.com...
>> On Fri, 10 Oct 2008 03:22:40 -0500, arehm <none.RemoveThis@000.com> wrote:
>>
>>>Hi, can anybody help give me a clue on what might be the
>>>problem with my 93 F150. The alternator drains the battery,
>>>and it's new and have taken it back to Pep Boys and had it
>>>retested and it passes ok. The battery is new also.
>>>
>>>When I start up my truck after it's been sitting for a few hrs
>>>or a day the battery gauge in the dash reads normal in the
>>>middle, but after idling for a few minutes the gauge needle
>>>drops down then starts to drain the battery.
>>>
>>>The alternator does get hot, but I don't see any
>>>problems with the wire harness or connectors melting or
>>>shorting anywhere. I have replaced the relay mounted on
>>>the inside fender wall near the battery, but still get the
>>>same results.
>>>
>>>Anybody have any knowledge? Thanks
>>
>>
>> If I understand correctly, it drains the battery when idling. This is a
>> common
>> symptom of a failed IAC (idle air control) which is not maintaining proper
>> engine idle speed. The alter will cut out completely when the engine
>> drops
>> below a minimum speed. This means everything that draws power is still
>> working
>> with no alternater support. Make sure the IAC is maintaining proper idle.
>> You
>> should probabl remove and clean the throtttle body at the same time. I
>> know it
>> has/had a sticker saying not to clean it but, trust me, they still get
>> dirty and
>> choked. If this doesn't do it, have a diagnostic scan for stored fault
>> codes
>> done. They are usually a free service at many parts stores on the hope
>> you will
>> buy their parts. You should not just buy parts. Post the code along with
>> any
>> display definitions. Someone here will probably be able to help you
>> interpret
>> any fault codes.
>>
>>
>> Lugnut
>
>I'm not so sure the IAC could be the culprit- I've had a few go bad on me,
>and the vehicle wouldn't idle at all unless I gave it the throttle myself.
>There was no way I could walk away and let it idle- it would be stopped
>before I opened the door if I tried. Still can't hurt to clean it and the TB
>while he's troubleshooting, though.
>That said, it could be some accessory dragging it down, like a direct wired
>radio or amp, or a bad ground from engine to chassis, or a bare wire. Or it
>could be the voltage regulator. If you know someone with a DC ammeter, you
>can test for drain with the engine off, at idle, and at high RPM.
>You might want to have your battery tested- even though it's new, it can be
>bad.
>
>SC Tom
>
>


If the IAC is dead or disabled, the engine idle speed should drop to it's base
idle speed which may be below the cutout point for the alternator. If the
engine dies when the IAC is not working or disabled, the base idle speed is not
properly set or the throttle bores are in really cruddy. My CV had a failed
IAC. The idle speed was right on the cutout point so that the engine had a bit
of a surge as it cutout/in. The normal current draw with a modern electroincally
operated vehicle can easily exceed 35 amps at idle. Without alternator support,
it won't take long to drain todays typical battery below the level where it can
operated the vehicle.

Lugnut
 >> Stay informed about: Help Needed for 93 Ford F150 XLT Electrical Problem 

> If the IAC is dead or disabled, the engine idle speed should drop to it's
> base
> idle speed which may be below the cutout point for the alternator. If the
> engine dies when the IAC is not working or disabled, the base idle speed
> is not
> properly set or the throttle bores are in really cruddy. My CV had a
> failed
> IAC. The idle speed was right on the cutout point so that the engine had a
> bit
> of a surge as it cutout/in. The normal current draw with a modern
> electroincally
> operated vehicle can easily exceed 35 amps at idle. Without alternator
> support,
> it won't take long to drain todays typical battery below the level where
> it can
> operated the vehicle.
>
> Lugnut

That may be true if the engine is warm, but from personal experience, when
the engine is cold and the IAC goes, the engine dies. MAF and TB were all
nice and clean (only had 8,000 miles on it), and, other than the idle, ran
fine. If I babied it until the temp was at operating temp, it would idle
fairly well, more like what you are describing.

SC Tom
 >> Stay informed about: Help Needed for 93 Ford F150 XLT Electrical Problem 

On Fri, 10 Oct 2008 18:24:41 -0400, "SC Tom" <sc.RemoveThis@tom.net> wrote:

>
>> If the IAC is dead or disabled, the engine idle speed should drop to it's
>> base
>> idle speed which may be below the cutout point for the alternator. If the
>> engine dies when the IAC is not working or disabled, the base idle speed
>> is not
>> properly set or the throttle bores are in really cruddy. My CV had a
>> failed
>> IAC. The idle speed was right on the cutout point so that the engine had a
>> bit
>> of a surge as it cutout/in. The normal current draw with a modern
>> electroincally
>> operated vehicle can easily exceed 35 amps at idle. Without alternator
>> support,
>> it won't take long to drain todays typical battery below the level where
>> it can
>> operated the vehicle.
>>
>> Lugnut
>
>That may be true if the engine is warm, but from personal experience, when
>the engine is cold and the IAC goes, the engine dies. MAF and TB were all
>nice and clean (only had 8,000 miles on it), and, other than the idle, ran
>fine. If I babied it until the temp was at operating temp, it would idle
>fairly well, more like what you are describing.
>
>SC Tom
>


It may be the ambient temp may influence whether it idles or not on cold start.
Here i GA, my problems have been during warm weather. With the CV, I hardly
could tell the engine was idling too slowly. The 4.6L is a very smooth engine
and the CV has no tach. It had no problem idling well below normal speed. The
Sable with the 3.0 started stalling 2 or 3 times after cold start but, would
idle fine after that. My 93 F150 with 5.0L simply idled too slow when the IAC
acted up and the volt meter would drop with the engine idling slow. It seems to
need 7-750 RPM to maintain voltage. With the IAC disabled, it turns just under
600 RPM. I still think it is a worthwhile angle to check and cost nothing to
do.

Just my $0.02
Lugnut
 >> Stay informed about: Help Needed for 93 Ford F150 XLT Electrical Problem 

arehm <none RemoveThis @000.com> wrote in message
news:1126662_b79f74a62008eb3e76e27a2ae1e57ed5@autoforumz.com...
> Hi, can anybody help give me a clue on what might be the
> problem with my 93 F150. The alternator drains the battery,
> and it's new and have taken it back to Pep Boys and had it
> retested and it passes ok. The battery is new also.
>
> When I start up my truck after it's been sitting for a few hrs
> or a day the battery gauge in the dash reads normal in the
> middle, but after idling for a few minutes the gauge needle
> drops down then starts to drain the battery.
>
> The alternator does get hot, but I don't see any
> problems with the wire harness or connectors melting or
> shorting anywhere. I have replaced the relay mounted on
> the inside fender wall near the battery, but still get the
> same results.
>
> Anybody have any knowledge? Thanks

It sounds like a bad alternator and your engine is running from the battery
instead of the alternator. Just because it's new (or rebuilt) doesn't
necessarily mean it's OK. Do you have an alternator tester of some sort (my
Vector/ B&D battery charger has one built in)? Or you could use a voltmeter
and check the battery voltage with the engine off and then with it running.
Off it should be about 12.5-13.5 volts and running it should be about
14-14.5 volts. If it doesn't go up when you start the engine I'd take the
alternator back again.


>
> --
> Posted at author's request, using moderated http://www.AutoForumz.com
interface
> Thread archive:
http://www.AutoForumz.com/Help-Needed-93-Ford-F150-XLT-Electrical-Problem-ft
opict230027.html
 >> Stay informed about: Help Needed for 93 Ford F150 XLT Electrical Problem 

On Fri, 10 Oct 2008 03:22:40 -0500, arehm rearranged some electrons to
say:

> Hi, can anybody help give me a clue on what might be the problem with my
> 93 F150. The alternator drains the battery, and itÂ’s new and have taken
> it back to Pep Boys and had it retested and it passes ok. The battery is
> new also.
>
> When I start up my truck after itÂ’s been sitting for a few hrs or a day
> the battery gauge in the dash reads normal in the middle, but after
> idling for a few minutes the gauge needle drops down then starts to
> drain the battery.
>
> The alternator does get hot, but I donÂ’t see any problems with the wire
> harness or connectors melting or shorting anywhere. I have replaced the
> relay mounted on the inside fender wall near the battery, but still get
> the same results.
>
> Anybody have any knowledge? Thanks

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 >> Stay informed about: Help Needed for 93 Ford F150 XLT Electrical Problem