Explorer swap alternator hook up

[Postalpal]

I have the 96 explorer 5.0 installed in my 72 Bronco , new build , I used everything from the original motor with a new painless harness
The 2 wires coming out of the top of the alternator (green/red & yellow)
EFI has told me
Yellow goes to fuseblock slot labeled ALT. (20A)
And that the green/red wire can go to 12V keyed
That’s how it’s hooked up

I know there’s a wire in the book listed as wire #914 that appears to be where they want you to hook the green/red wire to however I never could find that wire thus the reason I hooked it to a wire that has power when the key is on

It appears to not be working, I have to jump just to start (battery is new)

Is there a way to test the alternator or do I have this hooked up incorrectly?
Thank you for any input

 

[DirtDonk]

To begin with, the alternator has nothing to do with the starter not cranking. Zero.
If it does in your case, then yes, something is wired incorrectly.

If the battery is new and fully charged and functioning, which it seems to be because you can start it with a jump, then your starter circuit is connected incorrectly, or the neutral safety switch is buggered. Or something else we haven’t discovered yet.
Easy to test

When you say “jump“ though, are you jumping from another battery? Or are you simply jumping terminals at the starter relay/solenoid?

 

[DirtDonk]

The Painless harness wiring color should be the same. There should be at least one green with red striped wire hanging around somewhere. Yellow wire too, possibly, but I’d have to go back and look at the diagrams to see if they include one of those.
At this point too, I would be checking the power on the main connector at the alternator. Is there constant battery power on the yellow wire?
Measure the battery and measure power at the connector. Should be the same.
Is there a power on the green with red wire connector only with the key in the ON position? If both of those check out, there could be something wrong with the alternator.
That’s assuming anything is wrong with your charging system.
Because here again, you can’t check the alternator output if the vehicle won’t start. And if it won’t crank, it’s not a problem with the alternator.

 

[SLOWnEASY]

Can you clarify what you mean with jump to start? Are you jumping to get it to start cranking over or is it cranking over and not firing? What and where are you jumping.

 

[904Bronco]

Wondering if he has the PM starter, but has it wired like the original?

 

[DirtDonk]

EFI has told me

I assume this means Efi guy?

Yellow goes to fuseblock slot labeled ALT. (20A)

Are you sure that’s right? Yellow does not need to go all the way back to the fuse block, unless you’re using an existing yellow wire from the Painless harness? Should be yellow, or yellow with a white stripe, and there should be a full wire coming out that you can connect directly to the Yellow wire coming out of the connector.
Other than that, usually the yellow wire goes over to the battery side of the starter relay on the fender.

And that the green/red wire can go to 12V keyed
That’s how it’s hooked up

Keyed 12 V, but is it a green with red stripe wire in the Painless harness? You mentioned you can’t find it, but it should be there coming out of the back of the ignition switch, probably to the fuse panel, and then out through the firewall and readily available to connect the alternator to.
But as I mentioned in a previous post, you can easily check the power at the connector on the alternator with a volt meter.

 

[Postalpal]

Can you clarify what you mean with jump to start? Are you jumping to get it to start cranking over or is it cranking over and not firing? What and where are you jumping.

I just stuck my charger on it & it fired right up. Take the charger off and it won’t thank you

 

[Postalpal]

I assume this means Efi guy?

Are you sure that’s right? Yellow does not need to go all the way back to the fuse block, unless you’re using an existing yellow wire from the Painless harness? Should be yellow, or yellow with a white stripe, and there should be a full wire coming out that you can connect directly to the Yellow wire coming out of the connector.
Other than that, usually the yellow wire goes over to the battery side of the starter relay on the fender.

Keyed 12 V, but is it a green with red stripe wire in the Painless harness? You mentioned you can’t find it, but it should be there coming out of the back of the ignition switch, probably to the fuse panel, and then out through the firewall and readily available to connect the alternator to.
But as I mentioned in a previous post, you can easily check the power at the connector on the alternator with a volt meter.

I didn’t see it. That’s why I just hooked it to another non used wire that was key 12V. I will continue to search for it thanks

 

[Postalpal]

I assume this means Efi guy?

Are you sure that’s right? Yellow does not need to go all the way back to the fuse block, unless you’re using an existing yellow wire from the Painless harness? Should be yellow, or yellow with a white stripe, and there should be a full wire coming out that you can connect directly to the Yellow wire coming out of the connector.
Other than that, usually the yellow wire goes over to the battery side of the starter relay on the fender.

Keyed 12 V, but is it a green with red stripe wire in the Painless harness? You mentioned you can’t find it, but it should be there coming out of the back of the ignition switch, probably to the fuse panel, and then out through the firewall and readily available to connect the alternator to.
But as I mentioned in a previous post, you can easily check the power at the connector on the alternator with a volt meter.

Yes EFI guy , sorry

 

[Postalpal]

Yes EFI guy , sorry

These are my personal notes (incase you can read it ) but this is how i hooked it up from the information that EFI Guy has been great with communicating with me

 

[DirtDonk]

Yeah, Garry has been great with us all this time.
Hmm, how long has it been since he introduced himself here on the forums?

 

[DirtDonk]

I just stuck my charger on it & it fired right up. Take the charger off and it won’t thank you

Where exactly did you attach the charger? Just to the battery positive and negative?
If so, then it sounds to me like your battery is toast.
Either that, or the connection between the battery stud and cable lug is not good.
And that sounds like you have a pretty healthy charger, Which can boost a starter.

 

[SLOWnEASY]

If you have a meter I would suggest letting the Bronco sit overnight and pull a voltage reading of the battery in the morning. Here's a chart that will show the battery state of charge at various levels.

Also know that a 12v battery is made up of six 2.1v cells. So if you check the voltage and it reads 10.x volts it has a dead cell and needs to be replaced.

If the battery is good I would do as DirtDonk says and check all your battery to starter connections. If you have an extra starter relay you might try swapping that out just to see if it's the relay itself.