One wire alternator and voltage regulator F7078

I have a 1969 Rough Terrain Forklift ( Warner Swasey ) that was built on a Ford tractor driveline, I think a 4400. Anyway I was doing some work on the forklift and trying to trace all the wiring, some of which wasn't connected to anything. There were a bunch of wires near the alternator that were taped up - not used. I compared the original wiring diagram to what I saw and discovered that someone converted the original 3 wire alternator to a single wire. They did this by adding an F7078 Transpo voltage regulator unit to the alternator. The unit bolts onto the back of the alternator and makes connections to the alternator. One one wire then goes to the BATT terminal of the alternator.

I read a few articles on the web to understand how an alternator works. The fields have to be excited for the alternator to charge, and in some 3 wire units, they receive feedback near the batter to tell the alternator what voltage to charge at. Some get the feedback directly from the output of the alternator, which is really no feedback at all because it does not take into account voltage losses along the system.

Anyway, after understanding how the conversion worked I had one question, does the original voltage regulator that is mounted on the bulkhead still serve any function? 3 wires were still connected to it, but two of them were dead/disconnected on the other end. My assumption was that it was no longer serving a purpose, but I couldn't find any articles on the web that even mention the original voltage regulator. I finally call the good starter/alternator rebuild shop that I use. I explained my set up and he understood and told me that my original voltage regulator served no function. They just left it in place in case someone ever needs to go back to it. The job of the voltage regulator is to regulate it for the alternator.

Here is a picture of the Alternator in question with the F7078 Transpo voltage regulator on it.

That alternator does not look like the common Delco alternator used on many tractors. So with out know for sure what brand that alternator is hard to help you. It does how ever look like one I have seen on a number of old Jap cars

Looks like a Ford/Motorcraft, externally regulated alternator to me. What is the cast in lettering around the rear bearing. Looks like I see an M*********

You do not need an external regulator with the one wire Delco

That is not a delco. That is a Motorcraft.

Ah but that is not a delco of any sort

(quoted from post at 20:17:27 02/18/15) Ah but that is not a delco of any sort

Click to expand...

Clearly it is not a Delco unit. As someone mentioned, I too think it's a Ford/Motorcraft. The F7078 Transpo is available at a number of websites as a conversion.

With this post, I was reporting what I had found, especially if someone else has the same question I did - do you still need the original voltage regulator if the alternator has it's own voltage regulator? =No.