Alternator Mystery 10.00 Pay pal

[sleazebagger 10+ year member]

If you would like I can round up some of my good mechanic friends and take a look at it. Im stumped but Im local so maybe we can get something.

I appreciate that offer. you name a place and time and I'll free myself up to be there.

I would hope that between my wiz-friend and mechman we will get it done but you never know. Thanks man

Its pretty hard for anyone on a forum to figure this one out unless they have had a similar problem or know ford/mechman wiring like the back of their hand... lol

 

[infamous_e46 5,000+ posts]

probably has a bad rectifier

How to test a High Amperage Alternator

 

[sleazebagger 10+ year member]

The crazy bish of it is.... is that I'm getting enough current to run my system at full tilt but the voltage is not there... WTF!!!!

 

[sleazebagger 10+ year member]

How to test a High Amperage Alternator

yeah... I want to clamp it to see what kind of amps its pushing but I dont have the gear yet

 

[infamous_e46 5,000+ posts]

yo u check the fuses under the hood ?

 

[grimreper912003 5,000+ posts]

does your explorer have an external regulator? Also is their a fuse-able link in your charge wire?

 

[infamous_e46 5,000+ posts]

Could be the Alternator, you want it charging around 13-14V. It could be overcharging but then you would smell a rotten egg smell cause it would be cooking the battery. If it is undercharging then you would not be putting enough juice back into the battery to run the vehicle.

You could have a problem with the cables form the Alt. to the battery. If there is any extra resistance in the cables is will not allow volts to reach the battery. It could also be the battery. Even though it is new it could have a bad cell in it. One bad cell can destroy your battery and not allow the battery to hold a charge.

If all that is good check the connections at the battery and make sure they are tight, free of dirt or corrosion, and the wires are in good condition. If all else fails you could have something pulling down the juice and either a power wire shorted to ground.

f the alternator is sound, you need a voltage regulator. They are external on the Fords and easy to replace.

 

[infamous_e46 5,000+ posts]

ere is a diagram of the charging system in this vehicle, as you can see, it is pretty straight forward, with the ALT and the PCM as the major players. 99% of the time the fault is in the alternator, even getting a replacement doesnt mean that is is not defective. I would strongly sugest getting an alternator from a different supplier before replacing the PCM. Use the wiring diagram below to check all of the wires for poor connections or chaffing, and if you have a meter, you can do current and resistance testing of the circuit.

Read more: 2002 explorer 4.6 liter, just put new alternator and ... - JustAnswer 2002 explorer 4.6 liter, just put new alternator and ... - JustAnswer

 

---------- Post added at 07:45 PM ---------- Previous post was at 07:44 PM ----------

 

yo go check ur fuses i was reading there is a fuse that could pop and this would happen

 

[mikelaubach 10+ year member]

This is an "internal" regulator. It is not technically internal, but it is mounted to the side of the alt, so not the typical "external" regulator that folks think of when they think of Fords.

And he's already taken it to have it tested, and the place tested it fine.

This leads me to ask if the voltmeter is proper. LOL

 

[sleazebagger 10+ year member]

This is an "internal" regulator. It is not technically internal, but it is mounted to the side of the alt, so not the typical "external" regulator that folks think of when they think of Fords.
And he's already taken it to have it tested, and the place tested it fine.

This leads me to ask if the voltmeter is proper. LOL

Volt meter is good

And when I instal my old alt it charges at 14.2. I've had it in and out 3 times now with no problems

Checked all fuses and wires(at least 3 times)

 

[infamous_e46 5,000+ posts]

send it back to mechman then and tell them to go fuqq a goat

 

[mikelaubach 10+ year member]

Ok, so the part that they sent you mentions a 6G. This is a later alternator style than the 3G that I mentioned above.

They said that green/red is the turn on wire. But that should be feeding the dash light from the alt, not the turn on for the alt.

The Yellow/white should be the turn on for the alt. This is the A or AS pin in the connector, opposite from the R/G on the connector. This A/AS is the same on the 3G alt as well.

BUT, that still does not explain why your stock alt turns on, but this one does not.

NOR does it explain why you have the current you need, but not the voltage. If the current is there, then the alt IS outputting juice. (Or you are slowly depleting the battery.)

Have you tried to ground the alt chassis with a separate ground line? Maybe you need that potentiometer to up the voltage level. (Though I'd be surprised if it can increase the voltage by more than 10% as is required here.)

 

[ahole-ic]

Ok, so the part that they sent you mentions a 6G. This is a later alternator style than the 3G that I mentioned above.
They said that green/red is the turn on wire. But that should be feeding the dash light from the alt, not the turn on for the alt.

The Yellow/white should be the turn on for the alt. This is the A or AS pin in the connector, opposite from the R/G on the connector. This A/AS is the same on the 3G alt as well.

BUT, that still does not explain why your stock alt turns on, but this one does not.

NOR does it explain why you have the current you need, but not the voltage. If the current is there, then the alt IS outputting juice. (Or you are slowly depleting the battery.)

Have you tried to ground the alt chassis with a separate ground line? Maybe you need that potentiometer to up the voltage level. (Though I'd be surprised if it can increase the voltage by more than 10% as is required here.)

That does explain it man. Alternators use an ignition wire to tell it to engage. Some also use a wire to monitor engine rpm so they don't turn on at too low of a rpm. I'm thinking this alternator is basically standing by. Sure it might put out 12.1v but that is technically off. I would make sure you connect the turn on wire in the harness to the turn on wire on the alt plug. Next, most alternators have a voltage sense wire. They use this to monitor their output and this is how vcm's work. If you show it a lower voltage (via a diode or resistor) than what it is actually putting out, it will up its voltage and compensate.

 

[bubbagumper6 5,000+ posts]

The thing that stands out to me is that when the alt was tested out of vehicle they managed to get 14V out of it? Exactly how did they have the other (control) wires connected? You said you removed the main power cable and measured only 12V on the alternator's terminal so that rules out a short but it would make me think the alt is bad but like I said, that doesn't explain how you got 14V earlier.

 

[Germ305 10+ year member]

Its a ford....i own one too remember //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif