1 Wire Alternator - Excess Wiring Removal Writeup

[66P51GT]

There have been many threads on this subject but most everyone that installed the one wire alternator simply tied back the unused wires. For me, this was not an acceptable option since one of the reasons for installing the alternator in the first place was to clean up the unused wires in the engine bay - also to make room for an MSD ignition.

Please add feedback since I may have missed something. I will update this thread to reflect additional valid information.

These instructions are for a '66 with a 289. If you have a different year or have a 200 installed, instructions may differ.



I studied the wiring diagrams and cut here and snipped there and got it all to work fine while removing all the unused wiring. I am switching to a Volt meter so I do not discuss hooking up the stock Amp meter.

Short Version
I only had to cut two wires:

1. Solid yellow from the battery side of the relay switch (#152 in the attached diagram)
2. Green-red from the ignition switch to the regulator (#904 in the attached diagram)
3. I also shortened the black-yellow wire (removing the splice) and routed it above the radiator (#37 in the attached diagram)

Long Version

1. Follow the instructions to install your one-wire alternator. Mine was a 140 amp Powermaster.
2. There is only one wire hooking into alternator side of the harness. This is a solid yellow wire that is also connected to the black-yellow wire on the battery side of the starter relay. This is part of the feed for the amp meter. Cut the yellow wire about 4" from the end.
3. Remove the tape between the regulator wiring harness and the starter relay. This is the part of the harness that routed under the radiator. The other part of the same harness runs power to your lights.
4. From here you get a pretty good view of what neeeds to be cut and what can go.
5. There is a large black wire with yellow stripe. Don't cut this wire yet. This is the main power for the ignition switch. There is also a splice about 1/3 the way to the regulator. Cut everything away from the spice, keeping the black-yellow wire in tact.
6. You should be able to remove all of the wiring from the starter relay switch to the alternator. The only thing remaining should be the black-yellow wire and what is left of the solid yellow wire also hooked into this lead.
7. From the regulator side, you will have to cut away one or two of the plastic locks that help support the wiring harness splicing.
8. There is a green wire with a red stipe that should be exposed. Cut the greed-red wire. I left about 4" just in case I need to splice back into the harness at some point in the future.
9. All of the unused wiring should now be completely free and clear
10. I cut out the splice in the black-yellow wire and shortened it about 12" and routed it around the front side of the battery to the starter relay.
11. I used shrinkwrap to protect the end of the yellow and green-red wires I cut.

 

[66P51GT]

Here are some pics...

 

[GaPonyFarm]

You would have had a cleaner installation, and protected the ignition box better, if you would have mounted it, resting on the frame rail, just below and slightly to the rear of the battery tray bracket. When installing in that location, you don't have to worry about fluids, and its looks almost factory.

I'd also get a K&N Extreme air filter for daily use. That B&M (looks just like my Holley unit) is only good for show.

Also check your fan! It looks like you have at least one bent fin, which is a disaster waiting to happen!!!!!
Just some minor feedback.

 

[66P51GT]

You would have had a cleaner installation, and protected the ignition box better, if you would have mounted it, resting on the frame rail, just below and slightly to the rear of the battery tray bracket. When installing in that location, you don't have to worry about fluids, and its looks almost factory.

I tride placing it there by hand but the wiring didn't seem to fit right. The wires seemed to be crunched by the shock tower. I was also worried about water when driving in the rain. I have a catch can for the radiator that has not been installed so I'm not so worried about fluids in its current location. It was where the original regulator was so I thought it was a good place for the ignition.

Also check your fan! It looks like you have at least one bent fin, which is a disaster waiting to happen!!!!!

I think you are reverring to the last photo. I'll check it when I get home tonight. Tough to tell from the picture since the stock fan has a bevel cut on the back side. It also has about 300,000 miles on it so it would probably be a good idea to replace it anyway.

Thanks,
-Chuck

 

[66P51GT]

This particular fan has bevels on both the front and the rear. It also has a slight rise on each of the fan blades towards the tip. Yes, it is bent. But all of the blades are the same.

It may have come this way from the factory due to a standard A/C that was installed. I don't really know the answer but the fan is fine.

 

[66 BLAKE 96]

I bumped into this thread while cleaning out my favorites list. Some good one-wire info here for those (like me) that are considering this mod.

 

[Edbert]

The only key thing here is that the B+ wire from the alt gets back to the battery. You can connect it to anything that is shared by the positive cable that comes from the battery. I used the B+ terminal post on my late model starter for mine, in addition to cleaning up that nasty looking regulator assembly you can also dump the equally nasty looking solenoid from the fender with a late model starter that matches your late model alternator.

 

[thehueypilot]

That is also a unique battery hold down device. (More minor feedback) I just left my wiring intact so I could put it back to original if I ever wanted to go back that way. The regulator is still hooked up but does not control anything. You would be hard pressed to tell that it was not an original alternator except for the fat red wire coming off the back.

 

[Blown4.6]

Tell me this, if one were to incorrectly convert to a 1-wire alternator, what would the symptoms of this be?? I had a trained chimp do this conversion on top of a million other things during a restoration...I don't trust him.

Thanks

 

[krash kendall]

You have the same battery tie down as me! I have the red model though!

 

[Edbert]

Tell me this, if one were to incorrectly convert to a 1-wire alternator, what would the symptoms of this be?? I had a trained chimp do this conversion on top of a million other things during a restoration...I don't trust him.

Thanks

Worst case, your battery would not recharge.

 

[D Durden]

I guess I'm anal. I've had the MSD box inside with me since '93 . . .

 

[66 BLAKE 96]

I guess I'm anal. I've had the MSD box inside with me since '93 . . .

Not a bad idea there. Heck, if it's lasted since 93, that's probably why. Less heat, and weather to kill it.

Side note: Hey Dave! Say hi to Lisa for me.

 

[65 fastback]

I just had to revive this thread to give 66P51GT props. I installed my single wire PowerMaster alternator a couple of months ago and it has performed flawlessly. Before I did the installation, I did a search for "one wire alternator" and "PowerMaster alternator" and came up with 6 pages of matches. This thread was by far the most usefull.

Like 66P51GT, there was no reason for me to just tie-off any unused wires - they needed to be removed all together. His write up is spot on and even more clear once you unwrap the wiring harness. The only thing different I did was to keep the yellow wire, to power a future electic fan.

Thanks dude! This is what StangNet is all about to me, information sharing.

Tim

 

[D Durden]

Not a bad idea there. Heck, if it's lasted since 93, that's probably why. Less heat, and weather to kill it.

Side note: Hey Dave! Say hi to Lisa for me.

YOU GOT IT MAN!