Painless harness install with one wire tuff stuff alt help 74 bronco

[sambo]

Guys, I'm a complete newbie when it comes to electrical. This has probably been answered, but I'm not finding the exact answers.... Please help if you can.
So, The Painless instructions have been super easy to follow up until the engine compartment with my setup. I have a 1 wire Tuff Stuff alt fed with a 4ga wire from the positiove side of the battery and grounded to the motor. I'm not sure where I need to hook up the other wire to my start solenoid and MSD blaster coil. Would you guys mind advising me on witch wire to use in the new harness and which ones to cap off and hide in my wire loom?
Also, best place to wire a new voltage regulator, and should I disconnect the wires from the back of the factory amp meter in the cluster?

 

[DirtDonk]

So just to be clear here, your alternator is a “true one wire” alternator? Or is it simply an internally regulated alternator with multiple wire hook ups?
And what is its amp rating?

A one-wire literally only needs the battery charge cable to operate and that’s it.
There might be a second optional wire location that’s simply for a dash indicator light, but it just needs the one wire to work.
So we need to be clear about it, but either way your alternator has nothing to do with the starter relay or the ammeter any longer.

What other wires are you speaking of? Give us colors and number codes if you can. I think I know which ones you mean, but here again, it’s best to be perfectly clear.

You do not need an external voltage regulator with a one wire alternator. That’s why we need to know which alternator you have.
If you have a modern internally, regulated alternator, you get rid of the fender mounted regulator, and either terminate the wires and tuck them safely away, or repurpose them for some other use.

And no, you do not disconnect the wires behind the ammeter. You must leave it connected.

 

[sambo]

So just to be clear here, your alternator is a “true one wire” alternator? Or is it simply an internally regulated alternator with multiple wire hook ups?
And what is its amp rating?

A one-wire literally only needs the battery charge cable to operate and that’s it.
There might be a second optional wire location that’s simply for a dash indicator light, but it just needs the one wire to work.
So we need to be clear about it, but either way your alternator has nothing to do with the starter relay or the ammeter any longer.

What other wires are you speaking of? Give us colors and number codes if you can. I think I know which ones you mean, but here again, it’s best to be perfectly clear.

You do not need an external voltage regulator with a one wire alternator. That’s why we need to know which alternator you have.
If you have a modern internally, regulated alternator, you get rid of the fender mounted regulator, and either terminate the wires and tuck them safely away, or repurpose them for some other use.

And no, you do not disconnect the wires behind the ammeter. You must leave it connected.

ty, I will get my list and notes put together and reply later tonight or tomorrow.

 

[sambo]

ty, I will get my list and notes put together and reply later tonight or tomorrow.

So, the alt is a true one wire and I have it hooked to the positive side of the start solenoid with the positive battery wire. It is a tuff stuff 100amp and is grounded to the engine. The hot wire and ground are the only two connections on the alt. So, internally regulated.
wires in the harness I’m needing help connect in the new painless harness:
green/black
blk/yel 915
brown
blk 916
red/blue 957 (ing mod start signal)
red/blue 919 (start solenoid “s”)
then these wires also:
blk/red 956
blk 956 (reverse swt)
(2) red/blu neutral safety switch - not sure I need these, mine is a 3 speed manual
green 923 after market tach
red/green 920 coil
brown 970 coil to starter selenoid
blue 900 ign mod
grey/yellow 999 ign mod to coil
red/blue 957 ign mod
blue 900 ign mod
gry/yellow 999 ign mod to coil
again I really appreciate all the help, I can post pictures if needed

 

[Attac]

Sambo
Call painless. They are more than happy to walk you through it.
I too was a wiring newby years ago and called them every day and they always helped. I’m still what I consider a novice at wiring harnesses but I have installed 4 more without help since they walked me through the first one
Chuck.

 

[sambo]

Sambo
Call painless. They are more than happy to walk you through it.
I too was a wiring newby years ago and called them every day and they always helped. I’m still what I consider a novice at wiring harnesses but I have installed 4 more without help since they walked me through the first one
Chuck.

I will try to call them, I did send an email, but no response to that.

 

[DirtDonk]

Here are a couple that I can tell you off the top of my head.
Calling Painless is still a good move though, if just to confirm anything we say here.

So, the alt is a true one wire and I have it hooked to the positive side of the start solenoid with the positive battery wire.

Perfect. Alternator is basically a done deal then.

It is a tuff stuff 100amp and is grounded to the engine. The hot wire and ground are the only two connections on the alt. So, internally regulated.

Yep, done and done. The 4ga charge/BAT wire is your main connection, so some of the next few are either redundant, or simply not used.

wires in the harness I’m needing help connect in the new painless harness:

1. green/black

Have to get back to you on this one after reading the latest manual.
Speaking of which... How long ago did you purchase the harness? Recently or a long time ago?

blk/yel 915

Seems like I remember 915 being either the BAT wire to the alternator's BAT terminal. OR the power to the fuse panel from the starter relay through the Mega or Midi-fuse. My money is on the alternator, so check that.
If so, it's no longer needed because you now have a 4ga wire doing it's job.

You can choose to cut it off and terminate it safely, or re-purposing it to power other accessories.

brown

This will depend on which ignition system you're using.
If points or just a basic electronic setup, then this wire goes to the "I" terminal on the starter relay/solenoid.
If you have computer controlled EFI and ignition, you can choose not to use it.

blk 916

My guess is that #916 is your power hookup to the starter relay. This goes to the BAT side of the relay and is what gives the vehicle all it's power from the fuse panel.

red/blue 957 (ing mod start signal)

Are you using Ford Dura Spark ignition? Or anything with a computer that wants to see a start signal?
If the answer is no, then this wire is not used.

red/blue 919 (start solenoid “s”)

Just like it says, this wire goes to the starter relay's "S" terminal and is in fact the wire that gets things cranking when you turn the key to START.

blk/red 956

blk 956 (reverse swt)

If an original manual trans, this wire goes to the backup lamp switch on the steering column.
If an original C4, then this goes to the Neutral Safety Switch connection for the backup lamps.

(2) red/blu neutral safety switch - not sure I need these, mine is a 3 speed manual

I'll have to check the instructions to see if you simply disregard this wire, or if it needs to somehow be spliced to the other Red w/blue before it gets to the starter relay's S terminal. My guess is you ignore it, but I'd hate to be wrong and have zippity doo dah happen the first time you turn the key!

green 923 after market tach

Well, do you have a tach?
If so, connect it. Probably to a green wire on the tach harness, if it has one.

red/green 920 coil

This goes to the positive side of the ignition coil if you are using a standard ignition.

brown 970 coil to starter selenoid

This goes to the POSITIVE side of the coil if you are using it.
So here's where we have to hear from you about what type of ignition you're running, and if you are going to be running a ballast resistor or not.

blue 900 ign mod

Again, sounds like it's only for a Ford Dura Spark ignition.

grey/yellow 999 ign mod to coil

With a Ford Dura Spark ignition, this goes to the NEGATIVE side of the coil.

red/blue 957 ign mod

Ask Painless. Seems like that's too many Red w/blue wires and too many to the module since the one earlier was also a start signal to the module.
Or is this a duplicate, or an actual additional wire with the same number as above?

blue 900 ign mod

Repeat/duplicate? Or are there two of them?

gry/yellow 999 ign mod to coil

Repeat/duplicate? Or are there two of them?

again I really appreciate all the help, I can post pictures if needed

Always post pictures! Not only lets us know what you're working with and might point out something we can suggest, but it also satisfies our need to see what you're working on. Because we like pics!

Paul