Voltage regulator

Oliver 77, 6 volt everything, except battery. It's 12 volt. Coil is wired for neg ground, as is battery. I've been told I need a voltage regulator in line before the coil. Can someone explain,in simple terms ,what this does? Also what is a voltage reducer used for? I'm sure it's a simple answer.

Use a ballast resistor before the coil

A 6volt coil running on 12 volts draws too much amps and gets hot/burns out. The excessive amps also ruins a set of points in short order. To allow the use of a 6v coil in a 12v system, it is easy and proper to use a dropping resistor (commonly called a ballast resistor) to reduce the voltage to 6 volts. These were commonly used on cars and tractors from the 40s through today, on coil based ignitions. It is not an active voltage regulator like the one to the left in your images. it is a ceramic block or metal bracket with a resistor wire wound inside. 1966 Chevrolet 6 cylinder auto ignition resistor is typical. You could also replace the existing coil with a coil designed for 12v operation. It will be marked with words that say "no external resistor required"
Different topic:
If you want the tractor to be reliable, and original looking, You will need a 12v generator and a 12v regulator to replace those already on the tractor. If you want reliable charging ald less cost, you can put a one wire alternator on in place of the existing generator. If that is the case, let us know and we can help. Also the lights will need to be changed to 12v to avoid burning out.
Jim

Your starter motor will be OK as is. Jim

Where would I find such a thing? Local Napa?

So what does the one on the left side of picture do?

Yep, go to Napa

Thanks. Still playing with idea of getting 6 volt battery and a couple bigger cables. .........

It is a real Voltage regulatorused with a generator. It has several components inside. One of them disconnects the generator from the battery when the engine is off. (cutout relay). Another regulates the charging voltage by modifying the generators magnetism which causes its voltage to be stable when charging the battery running the lights. The other device is (I think with no part number) a variable resistor from the world of electronics. Jim

Used in the charging circuit to control the charging voltage, and has a cut out so when it is not charging, it doesn't drain the battery. You need the one on the right in the ign circuit to use a 6 volt coil on 12 volts.

I?m not a fan of 6 volt, every thing I own is converted to 12 volt, some folks like staying original and keeping 6 volt systems, to each his own. 12 volt is my choice

Get one for an 85 dodge v8 pickup. It will have about a 1/4 inch mounting hole in it.

So I could swap generator for alt, lights, and coil? Simple?

Grandpa, if you are trying to keep it factory original, as in for show purposes, or if you just want to keep it original, then stay with the 6v system. Your choice.

But be ready to spend more money. The 6 volt batteries are known for only lasting a year or two. The Optima batteries are supposed to last longer, but more expensive and would not be original.

For a 6 v system to function, everything has to be right. A healthy engine, clean fuel system, well tuned ignition system, good starter, large gauge cables, and a properly functioning charging system.

The charging system is the catch. The generator can be repaired if needed.

It's the regulator that will likely be the problem. All the new regulators are generic, fit-all, imports. The original regulators were much better built, and built to match the generator exactly. It is beyond feasibility to even attempt that now, the shelves would be loaded with regulators that may sit there for 50 years! So you take what you can get, and expect it to go bad in a very short time.

The alternative is to convert it to a 12v alternator, with negative ground. Simple, cheap, and dependable. The battery will now match anything else as long as it will fit in the box, no confusion when jump starting.

There are some drawbacks.

It will no longer be original, but you can save the parts, just in case...

Some models, depending on how rugged the starter is, and how many times a day it gets started, have starter problems. The 6v starter will slam the gear into the flywheel harder operating on 12v. Some handle it well, some don't. If your starter, or flywheel gear is already worn, it may finish it off. Also be sure the timing is not set too fast causing kick back, and always wait until the engine is stopped completely before hitting the starter again if it kicks out when cranking.

There are a couple of other alternatives, but they get pricey.

There are reverse polarity 6v alternators. More dependable than a generator, and lets it stay 6v positive ground.

There are alternators disguised inside a generator housing. Keeps the original look, but with the dependability of an alternator.

Two not so simple things are the wiring and mounting the alternator so it runs true to the belt. Most autoparts have one wire alternators that self excite (start charging when the engine starts) some older versions require more rpm to get them started charging. A 3 wire setup is preferred by me, and is pretty simple to install. If there is cramped room a Hitachi 14231 will be far smaller and as easy to wire as a Delco 10SI we can help with wiring if you decide. Jim