806d generator to alternator swap

Install the alternator.

Take both wires that were connected to the generator and connect them to the alternator's B terminal.

Connect the alternator #2 terminal to the B terminal of the alternator or the B terminal on the starter solinoid. The purpose of this wire is to allow the alternator's internal regulator to sense voltage output of the alternator. Connecting it to the B terminal of the alternator is quick, but if you connect it to the B terminal of the starter solinoid, the alternator's regulator will get a better idea of the voltage acually getting to the batteries.

Next, connect the alternator #1 terminal to somthing that gets 12 volts only when the key switch is on. On a diesel, the easiest place would be the stud on the back of the fuel level guage that has the wire from the key switch connected to it. If you were doing this on a gas tractor, you would connect to the wire from the key switch to the coil. You'll want a diode between the #1 terminal and the fuel guage, connected so power can only flow to the #1 terminal, and not back from it, because power will try to backfeed from the #1 when the engine is shut off. This is more critical on a gasser where this wire is connected to the ignition system, but it is still a good idea.

There are alternator conversion harnesses alvalible made up of the plug that plugs into the 1 and 2 terminals, a diode, and the wiring for the #1 and #2 terminal connections. I think you can get them at places like TSC.

Finally, take all four wires connected to your generator's regulator and connect them together and tape them up good.

If you really want to get it right, late 06's came with alternators. You can buy entire new harnesses from Case-IH.

Remove the generator and regulator. Mount the alternator and tighten the belt properly and so forth. Run a wire from the large stud on the alternator to the same place where the regulator's "bat" wire went. Without looking at a wiring diagram, I would imagine this wire will go to the ammeter. It is advisable to use #10 AWG or larger for this wire. Run a wire from pin 2 on the alternator to the same large stud on the alternator. Run one more wire - from the switched side of your key switch to pin 1 on the alternator. Since you have a diesel, you would not need any diodes, lamps, or whatever in line with this wire.

One last item: If your battery had the positive post tied to ground, reverse the battery to ensure that your negative post is tied to ground. You would need to reverse all your ammeter connections too.