I just realized I ordered a 1 wire alternator instead of a replacement 3 wire. Instead of returning it I am hoping to convert my wiring to a 1 wire alternator. I searched old threads but many of the pictures wouldn't load for me, or the diagrams were a bit over my head.

Does anyone have a simple diagram to help me get this conversion going? My truck is a 75 F250. Thanks!

 

I use a 1 wire unit. First thing I recommend is to get a battery that has both the top post and side post. This will greatly ease your hook-up. I ran the alt wire to the positive side post and used the top post to go to starter solenoid/truck wiring. When you install the alternator, make sure that you have a properly rated fuse between the alternator and the battery. You also need to make sure that the main wire going to the truck(can't remember the color) is hooked up or you will find yourself with no power when you try to start. After everything checks out, you can carefully remove the old alternator wiring harness and voltage regulator.

 

Can you take pics of your starter solenoid where the battery post is connected?

 

Filthy I know...I have a new solenoid on the way.

 

1st pic: I believe that the black with yellow stripe wire is what supplies the truck with 12v. Make sure that remains hooked up. I'm not sure what the other wires hooked up at that connection go to.
2nd pic: Large wire of course is the alternator wire. Looks like that one has a nick in it. Make yourself a new wire and make it a sufficient gauge for your alternator. Remove tape or sheath carefully and remove harness from truck. Do not discard until your new unit checks out.
3rd pic: Wiring to voltage regulator? If so, remove tape or sheath carefully and remove harness from truck. Do not discard until your new unit checks out.
Finally, make sure all your connections are cleaned, if not new.

 

make sure to take pics of your hook-ups so that you can reference them if needed.

 

Will do. Another question.

The large wire on the right of the solenoid, going to the starter...Is that the only wire going to the starter? I thought I took pics of the starter wiring when I removed everything but can't seem to find it. I don't see any other wires in my engine bay that would feed to the starter motor. I just want to have my wiring ready for when I drop the motor in.

 

Yes, lone cable on right side of solenoid is the starter wire. Do yourself a big favor and get the battery I recommend.

 

The instructions say the #1 terminal (or R terminal) goes to the battery warning light. Which colored wire is that at the relay?
Do I need to do anything with the #2 F terminal?

 

I don't know which wire that would be. Awhile back, I fabbed my own wiring harness for the truck, so all the color coded wires are gone. One thing I can say is to install a volt meter gauge in the truck. This will tell you all you need to know about the battery. I'm not familiar with this F2 hookup. Does your instruction manual say? If not, what is the make and model of the unit?

 

Does your truck already have full gauges with an ammeter? Or is it mostly indicator lights?
This is not a Ford alternator, so does not connect the normal way. It's a GM unit, and your truck may not even have a battery indicator lamp for that wire to connect to in the first place.

Are you sure that this is a true 1-wire alternator? Is that what they said? What brand and part number is it?
And how many amps output is it capable of? Is this why you bought a non-Ford part, because it's a high-output rated one?

Paul

 

The brand is a Tuff Stuff 7078NF Ford 1G case style 100 amp. It is advertised as a 1 wire alternator.

I bought it because I also purchased a March serpentine pulley system that required a 1G case style alternator to work with the brackets it came with.

I also purchased a voltmeter gauge to hook up in my truck.

 

I checked your model on the Tuff Stuff site. According to its description, it is a 1 wire hybrid 100A unit. There is no mention of the F2 wire in the manual. I would call Tuff Stuff to get that info. Also, the R1 wire is to be hooked up to a warning light that comes on if the alternator is not charging. I would leave this unused and install a voltmeter. The voltmeter will tell you if the alternator is charging and you would not have to wait for a warning light, which would be too late.
Hi One Ton. I have a Tuff Stuff 100A true 1 wire unit. Even though it is GM principle, it is built for a Ford engine. I picked this unit because I was losing belts with the 3G on my 460. I have had it going on 3 years now. I love it!

 

Thanks 84espy. So I'll run a 4 gauge wire with an inline fuse from the alternator to the battery, then the wire from the battery to the starter solenoid Hook up my voltmeter and get rid of the original 3 wire harness. Sounds too simple...

 

Hey espy! Yeah, Tuff Stuff stuff is good stuff.
Glad you're having a good run with yours. Love it when a good charging system plan comes together!

Were your belts breaking? Or flipping you off, so to speak?
Must be a lot of rotating weight in those 3G's. Squealing belts are the norm when replacing them on v-belt setups. Not sure I've heard of any that were flipping or snapping belts though. Maybe you were getting more use out of yours than most, and the belts just couldn't take it.

Hope we didn't jinx it just by saying good things about it!

Paul