Solved Odd ball alternator for 1998?

[whitey818]

My daughter has a 1998 Explorer with 4.0 V6, the alternator went out and needed a quick, cheap fix.
Took it off went to junkyard with old in hand and found one that looked to match up perfectly in another Explorer. Took it home installed it but went to wire it up and saw ours doesn't have the single square plug stator wire that loops back to the alt harness? It is charging at 14.1-14.2 volts at idle but doesn't come up much when you rev the engine but the battery light stays on constant.
Is that wire just for the idiot light or does it serve another purpose? I know the one I grabbed at JY had it and didn't realize ours didn't when I grabbed it. Not sure I am explaining it right so its the "S" wire in picture.

 

[BrooklynBay]

Return the alternator, and get one that matches what you have.

 

[boominXplorer]

You got one from an OHV v6. You need one from a 4.0 SOHC OR 5.0 V8

 

[whitey818]

Thanks for the quick responses! Didn't even know there was a difference, will have to call and see if they would let me swap it out tomorrow. It looks and bolts up identical, thought I was lucky, lol.

 

[whitey818]

Out of curiosity, if I can't return this, is there any harm other than the idiot light being on? It does seem to be charging adequately.

 

[BrooklynBay]

There should be a return policy on it if you could prove that it's not the correct one.

 

[CDW6212R]

There are three bolt holes in each of the two Explorer alternators, but they aren't the same pattern. Only two bolts will line up if it's the wrong alternator, or you've got a completely different alternator etc.

I bought my 99 SOHC truck without an alternator on it, and they gave me one from another truck. The dash light will stay on, and it isn't charging properly. The older OHV alternator is a 3G unit, and the V8 or SOHC takes a 4G alternator.

 

[whitey818]

Thanks everyone, went and swapped it out today and works like a charm. I do believe it was the only SOHC there, looked through nearly every Ford in the yard and all was OHV.

 

[CDW6212R]

Well done, make it look easy.

 

[BrooklynBay]

Thanks for the update. Your thread is now marked solved.