mountaineer alternator on a 91 explorer..

[Blue91Ex]

Hey guys, so i bought this 130 amp alternator a year ago from a junk yard to put on my 91 but never did. it came out of a v6 mountaineer, is bolts on the same but the alternator on my 91 has an extra, little plug on it with 2 wires, the newer one does not have this. My alternator died this morning and i cant afford a new one. will the newer alternator work in my truck? If anyone has a solid answer it would be greatly appreciated..

 

[natenkiki2004]

Could you post a picture? My 1991 has a 3-wire plug and a 1-wire plug but it's a reman unit and one of the wires is spliced, it might be what you need to do.

 

[Blue91Ex]

Could you post a picture? My 1991 has a 3-wire plug and a 1-wire plug but it's a reman unit and one of the wires is spliced, it might be what you need to do.

i dont hve a picture, the old alternator has 2 plugs, one a 3 wire and i thought the other was a 2 wire, might be 1, and then a big heavy gauge wire on the back that bolts on, new alternator doesnt have the smaller plug. which wire was spliced and how?

 

[natenkiki2004]

Have a look:
https://dl.dropboxusercontent.com/u...rer/Pictures/CameraZOOM-20150304130231179.jpg

I haven't messed with the alternator myself but I think the middle wire (white with black stripe) in the 3-wire plug comes off and goes into the single-wire connector.

I'm not sure how or why the alternator is wired the way it is in my 1991 but it works so I haven't needed to dig into it.

 

[FR-425]

The lug on the back is the main output:

The 3 wire jobby energizes the fields.

The other 1 or 2 wire is for the gauge: 1 wire for idiot light or range type gauge: 2 wire for a gauge that displays voltage numerically where zero is not the minimum. This type of gauge will also show battery discharge without the engine running.

So yes it'll work. As long as the 3 wire and the main are connected.

You just won't have a working gauge.

 

[Blue91Ex]

The lug on the back is the main output:

The 3 wire jobby energizes the fields.

The other 1 or 2 wire is for the gauge: 1 wire for idiot light or range type gauge: 2 wire for a gauge that displays voltage numerically where zero is not the minimum. This type of gauge will also show battery discharge without the engine running.

So yes it'll work. As long as the 3 wire and the main are connected.

You just won't have a working gauge.

one of those 3 wires is a jumper wire, it goes from the big 3 wire plug to the smaller 1 wire plug
the new alternator doesnt have the 1 wire plug at all, so the third pin wont have anything going to it on the new alt. im guessing this is pcm control wire but not sure, it would have to go to something..

 

[FR-425]

Here's the diagram for a 91 Ex and a 98' mounty.

They are the same:

Click on this link.
Then the big red button that says "wiring diagrams"
It will auto fill the rest.
Then click search.

http://www.bbbind.com/free_tsb.html

http://www.bbbind.com/free_tsb.html

 

[FR-425]

What year was the mounty?

 

[Blue91Ex]

it was either a 96 or a 98 i believe

 

[FR-425]

And yes you are correct the jumper is actually the stator. I'm atarded.. ..

One jumps from the rectifier to the regulator. Which is the one your missing, Not gonna work without that!

One is the gauge. (NO computer involvement in the charging sys)

And finally the power from the fuse panel. (you may want to check the fuse first) (if you haven't already) before you replace the alt.

 

[Blue91Ex]

i see, it looks like that third wire is still there but internal, but i dont understand why the plug would have 3 pins if that wire was still supposed to be there.. there isnt anywhere for it to go.. anymore since the new alt doesnt have the other plug..

it looks liek i may have to swap the position of a coupel wires though. on that 3 pin plug..

 

[Blue91Ex]

And yes you are correct the jumper is actually the stator. I'm atarded.. ..

One jumps from the rectifier to the regulator. Which is the one your missing, Not gonna work without that!

One is the gauge. (NO computer involvement in the charging sys)

And finally the power from the fuse panel. (you may want to check the fuse first) (if you haven't already) before you replace the alt.

how exactly would i make that work? there isnt anywhere that that jumper wire can g0o, where did it go on the mountaineer? there isnt a plug for it but there is a pin.. the stator and regulator are still on the alternator right?

 

[FR-425]

Yea, its like you said the jumper is probably internal.

I wouldn't try to fit that in there. if you get it wrong you will fry some wires.

Money is really that tight? it may cost you more if you bodge it up.

 

[Blue91Ex]

what would fry? the 3 wires on that plug are the same gauge, everything is fused. i just dont understand why there is a 3rd pin on that plug for the newer alternator..

 

[Blue91Ex]

maybe the gauge and light are on different circuits so the new alt would normally run the gaueg separate from the light and the 91 ran guage off another circuit entirely?

 

[Blue91Ex]

Well i ended up ordering a new alternator instead.. soprry if anyone else might come here to find out for themselves if it will work, I'm not going to try it and risk damaging anything.

 

[natenkiki2004]

I would have tried it. You bought a new alternator anyway. I'd imagine the wires are the same. There's only really 2 wires going to the alternator, they're just split into 4. The main battery lug on the back also feeds the yellow wire in a round-about way. The white wire basically jumps a connection externally. The last wire, I think a green one goes to ignition so it powers the alternator field when you turn the key. Something like that anyway.

 

[RandomNerd2000]

I have the answer I think even though you got a new one. Some time ago, we had a V10 Ford that needed an Alternator, and we ended up eventually having a within fault, but the one pin jump is a signal wire, one is a steady voltage, one is a charge wire afaik.