2002 windstar Battery light came on tried two alternators still On.

[desimunda]

The alternator just doesn't charge enough. Once I rev up high I am able to charge and all lights that come on dashboard(brake, ABS, airbag) go away.

Tried one new alternator and one used one.

any body get to the bottom of this?

[12Ounce]

Originally Posted by desimunda

The alternator just doesn't charge enough. Once I rev up high I am able to charge and all lights that come on dashboard(brake, ABS, airbag) go away.

Tried one new alternator and one used one.

any body get to the bottom of this?

Have them bench-test the alternator before you leave the store... I've had two test bad right out of the box. (AutoZone)

[desimunda]

so as far as I can tell the battery is OK. After some highway driving battery has a charge of 12.48volts.

the B+ on the alternator has the same voltage so the positive cable and fusible links are OK too I would assume.

me thinks has to be the alternator or the PCM?

anybody know where the PCM is located?

[phil-l]

What voltage are you seeing with the engine running? A properly-charging alternator paired with a healthy battery and correct wiring should mean you see on the order of 13.8 to 14.2V, measured at the battery terminals.

[desimunda]

Originally Posted by phil-l

What voltage are you seeing with the engine running? A properly-charging alternator paired with a healthy battery and correct wiring should mean you see on the order of 13.8 to 14.2V, measured at the battery terminals.

only seem to get this with high RPM. but that is the case with 3 alternators! after I get them tested tomorrow I think I will know more..

[desimunda]

so bench testing showed both alternators are not putting out enough amps.

so on to trying out the 3rd one which I should get tomorrow.

thanks all.

[desimunda]

Originally Posted by desimunda

so bench testing showed both alternators are not putting out enough amps.

so on to trying out the 3rd one which I should get tomorrow.

thanks all.

Got another new one out of the box and still got battery light.

[12Ounce]

Was it bench tested before installing?

[desimunda]

Originally Posted by 12Ounce

Was it bench tested before installing?

no i did not. are you saying the van can negatively affect the alternator?

[12Ounce]

Originally Posted by desimunda

no i did not. are you saying the van can negatively affect the alternator?

Of course the van can destroy the alternator ... but it's more likely the alternator was "just bad". But how will you ever know if you don't first test the alternator before installing? That's what I was encouraging you to do... bench test even if new!

[desimunda]

Originally Posted by 12Ounce

Of course the van can destroy the alternator ... but it's more likely the alternator was "just bad". But how will you ever know if you don't first test the alternator before installing? That's what I was encouraging you to do... bench test even if new!

I guess I will have to with the next one. I have a small battery/alternator tester and had that plugged into the 12v outlet and it showed the alternator intermittently unable to put out more than 13.4 volts.

just curious how can the van negatively affect the alternator this quickly?

[phil-l]

Are all of these alternators from the same manufacturer/rebuilder?

[desimunda]

Originally Posted by phil-l

Are all of these alternators from the same manufacturer/rebuilder?

yes TYC brand new apparently and it has a testing page include which might be copied and put in all boxes!

[desimunda]

So for my new alternator from TYC rated at 135 amps. just found out from ford dealership it should only be a 110amp alternator.

this would burn out the battery earlier but do you guys think the 135amp would not put out enough voltage for the battery light to stay on as it has?

mind you I ran with a TYC since june of last year.

[12Ounce]

No, it doesn't work that way. More amperage is always better ... up to a huge value. It is only an indication of how much heat the alternator can safely dissipate. The higher the amp rating the more current the van is allowed to draw from it ... while it holds together.

It doesn't necessarily mean that the battery will be charged any more quickly ... the battery has its own internal resistance that limits that ... but it does "allow" the battery to be charged more quickly without harm to the ALTERNATOR.

My current alternator is rated at 165 amp. If a larger one is available when replacement is needed ... I will buy it.