Need help with wiring on an Oliver Super 55

Biglurr54 · Nov 1, 2017

I blew the PTO clutch out on my Oliver Super 55 when brush hogging. I split the tractor replaced the PTO clutch, some seals, and the pilot bearing while it was apart. I am putting it all back together and I am struggling with the wiring. It was converted to 12v neg ground at some point. The wiring was a rats nest and a mess. One wire shorted out and burnt other wires a while ago. Needless to say, its time to completely rewire it.
I am struggling at two places. One is the generator/alternator. It looks like a GM alternator. It has one lug for a heavy wire and then it has two wires on a plug. The one wire on the lug went to the ammeter. One wire on the plug goes to a small diode thing and then to a 4 wire voltage regulator. The other wire on the plug goes to another place on the voltage regulator. One other wire on the voltage regulator goes to the coil side of the resistor and the last wire on the regulator is a complete unknown to me. It seems like someone took the generator off and kept the voltage regulator. Where does the one unknown wire go for the voltage regulator? Do I need the voltage regulator if it is an alternator? I am wondering if who ever did the conversion kept the original voltage regulator and stepped it down to 6 volts through the resistor.
Could/Should I switch the old coil out with a new 12v coil and get rid of the resistor? Would that burn out my points?

Tractorable · Nov 1, 2017

I have an 8N with 12v conversion. It seems that a lot of 12v conversion kits come with chevy alternators.

I guess my question is, do you just want to get the tractor running? Or do you plan to do an entire re-wire?

If you're going to do a complete re-wire and keep the 12v conversion I'd first determine if your alternator is internally regulated, then figure out if you have a 6v or 12v coil. Ideally you should have all 12v components including the battery.

Post some pictures and let us take a look at it.

ovrszd · Nov 1, 2017

I agree. Gotta decide what the end goal is.

Were it me, I'd do a complete convert using an internally regulated alternator. Simplifies things a lot.

As mentioned, post some pics. You'll get plenty of help here.

If not, try starting a thread in the "Vintage Tractor" forum here.

http://www.tractorbynet.com/forums/vintage-tractors/

Zebrafive · Nov 1, 2017

The alternator sounds like a GM 3 wire alternator.
No regulator needed.
Main lug goes to battery positive, usually connects to main lug of starter motor.
The plug will have one wire come from the ignition switch, HOT only when key is in RUN. It "tells the alternator to charge. This wire must be switched off when not running.
The second wire of the plug "tells" the alternator the state of charge of the battery, it can be "looped" to the large stud of the alternator.

They may be using wires from the old voltage regulator to provide the switched 12v to start the alternator charging, and another wire to tell the alternator battery charge level.

For the coil, first I would get a 12 volt coil if system was 6v and converted to 12v.
The positive should have two wires. One wire should be 12v, HOT, ONLY when starting. It can come from the starter solenoid, if there is a terminal marked "I" for ignition on the solenoid. Or your ignition switch may have a terminal that is HOT ONLY in START, that does NOT go to the starter solenoid. You want to make sure the resistance wire from the coil does NOT back feed to starter solenoid engaging the starter. If you do not have either of these places to hook up this wire to the coil, you can use the wire that "triggers" the starter solenoid, BUT it MUST have a diode in it to prevent back feed from the coil resistance wire. This puts 12v to the coil ONLY when starting for easier starting.
The second wire will be either a resistance wire, or have a resister in it. It will come from the ignition switch HOT in RUN. It lowers the voltage at ALL times when running to keep from burning the points.

Biglurr54 · Nov 1, 2017

I am looking to get the tractor running and clean up the wiring. Once it's together and cleaned up I will be selling the tractor. I bought a ford 3400 so the old green machine will move on to serve someone else.

The current coil is a 6 volt coil. There is a ballast resistor before it. The original ballast resistor was broken so I am replacing that as well. I'll take a couple of pictures of the alt/gen. And the coil.

Biglurr54 · Nov 1, 2017

Heres a pic of the alt/gen and the regulator. The wiring has been removed. I'll get a better pic tonight.

Biglurr54 · Nov 1, 2017

This one shows the wiring mess, the coil, and the resistor.

Dave M7040 · Nov 1, 2017

Biglurr54 said:
I am looking to get the tractor running and clean up the wiring. Once it's together and cleaned up I will be selling the tractor. I bought a ford 3400 so the old green machine will move on to serve someone else.

The current coil is a 6 volt coil. There is a ballast resistor before it. The original ballast resistor was broken so I am replacing that as well. I'll take a couple of pictures of the alt/gen. And the coil.

How do you know the coil is 6 volts? Ballast resistors were used on 12 volt coils that were designed to use a resistor.

The trick when using a ballast resistor is to automatically take it out of the circuit when starting thus producing a hotter spark for a few seconds until the engine fires and then put the resistor back in the line..

Run a second wire to the coil. The first being from the ballast resistor. Connect the second wire to the start position on the ignition key switch. Now when you are cranking you are providing full 12 volts to the coil. As soon as the key is released, the starter stops and so does the full 12 volts to the coil.

Dave M7040

Biglurr54 · Nov 2, 2017

My tractor has a 2 position key. Off and run. There is a starter button that goes to a relay on the starter.

I think I am going to take the voltage regulator off line. I will run a wire from the #1 post on the alt to the on position on the key. I will jump #2 post to the lug on the alt. I will run a wire from the alt lug to the ammeter, then to the starter. I will jump off the alternator main wire at the ammeter to the key switch. From the on position on the key switch to the starter button. I will add a second lead to the starter button with the on switch lead to the ballast resistor.

Should I run a jumper from the starter button on terminal to the coil? This would provide a full 12v to the coil when the button is pushed to engage the starter but it would cut the 12v to the coil when the button is released.