Jd 70 regulator

Maybe the key is that the L connection on the regulator needed to be there to coddle the batteries available in the 40's and 50's. They're closer to Alessandro Volta's first pile than the things you get off the shelf today.

You said it was running OK. I'm guessing you're not doing 'round the clock planting or harvesting with it -- so lights aren't a big problem. Also guessing that the lights are drawing off the battery line and the battery or batteries in there are less than 5 years old. In that case -- why mess with it?

That's just the view from here at the lazy guy's school of wrench turning and deductive circuit troubleshooting. If you're from the fastidious guy's school of mechanics and correct restoration; then by all means use the L line as originally intended. Sad in a way that you probably can't find a new 1957 battery to appreciate your work. Those new DieHards just don't care anymore. (humor and puns always intended).

Least we all appreciate the spirit of the 70 if not always the obsolete details therein.

regards,

Steve

Understand about the 3 terminal voltage regulator. My 60 only has three as well. That's why I was doing the mental gymnastics, trying to back in to what the terminal was for based on cars I've worked on. All the books I have on it are out in the barn with the bats and the raccoons at night, so I did it from memory.

Sounds like your 70 has all the trimmings! I've seen the fenders alone go for nearly 500 bucks on eBay -- even more for the flat top fenders on the 30 series. They may be worth more if you sold them separately. But then again people get in to bidding frenzies on eBay and at auctions, and sometimes they don't. You have to learn how to present them so people just can't bear to live without them.

Funny thing about number series JD tractors. The little 40's and 420's are going for as much or more than 70 row crops. But anyway... for wild guesses on prices... I'd start at 2500 to 3000 for a basic 70 in that runs and looks good here in Ohio, Indiana, Illinois. Then add a few hundred for the fenders and another few hundred for the power steering. The loader is the big adder. You might be able to get another 2,000 for that. Loaders are a hot item. Seems everybody needs one on their tractor. These are all guesstimations, you understand. There was a guy who posted on here a few days ago who had just bought a 70 with a loader. You might give him a shout and see if he'd care to share his views on pricing. I put in a link to his post below.

The downside to pricing right now is that farmers are looking at dry weather and low crop yields. Guys with hobby farms are seeing their 401K retirement accounts dwindle, so they don't feel as rich as they did a year or two ago. You might have read that retail sales were fairly sparse last month, and that people are doing a lot more shopping at WalMart than they are at any expensive stores. Old tractors like ours are more toys than tools -- so I imagine the prices are or will be affected. The good thing is that this is America, and hope springs eternal. Next Spring -- when tractors and lots of other things normally sell at a much better rate, and for higher prices --you could be looking at a completely different story.

I'm guessing you're also thinking about getting a sharp car or truck, maybe going to college, and all the other fun hopes and dreams a guy has when he's in FFA. Forty years from now you might regret ever selling that 70. But for right now you want to do and experience as much as you can. So more power, and good luck to you.

P.S. I don't think they'll give you any grief in FFA about that L terminal. If they do, a good explanation of why it's there and why you decided not to use it should smooth it all over. Might also be a good exercise to figure out how it works inside. In the world we live in, where everything seems do-able with a few lines of digital code, the analog magic done in that little voltage regulator box with some coiled wire, a few springs, contact points and a resistor here and there is something to be respected, and the guys who designed those things are to be admired -- even if they gave you an L terminal you don't need. Somebody's 1950 vintage car with headlights, heater fan, windshield wipers, radio blasting and maybe an electric convertible top did need it. When all you have are two or three lights and maybe a cigarette ligther in your 70 pulling on a 2001 vintage battery, it's kind of doubtful.

take care,

Steve

• Guy who just bought a 70 w/ loader

Here's some theory and a few thoughts from memory that may help sort it out.

There's gotta be a terminal for the field windings and another for the armature in the generator -- the generator being regulated by increasing or decreasing current flow to the windings by varying resistance inside the regulator. I think they're labelled F (field) and A (armature) on the Delco or JD regulator.

Then there's got to be a connection to the regulator's limiting circuit to prevent the battery from getting overcharged at higher RPM, and charged as much as possible at low RPM or heavy demand loads. That's connected -- strangely enough -- to the battery by way of the amp meter. I remember it being labelled B, for battery. That's three terminals, and so far we should be tracking to the way your 70 is setup.

From messing with other regulators on other machines, the most I remember are 5 terminals. The first was labelled G for Ground (or E for Earth on British iron). The second terminal is a subset of the battery charge limiting circuit - B. It's variously called AI, I (for indicator on a Ford I remember), or B1 / BI for battery indicator, etc. Also, this line in some older cars runs to the head and tail lights as well as the idiot light because keeping the lights bright and the battery charged is one of the most important jobs a car's regulator has at night. If you run the lights through the regulator's limiting circuit it's easy to compensate for both night and day driving - and the different charge levels the battery needs in both circumstances. So I'd put my money on L = lights. Of course it runs to a switch, like you say, for the head and tail lights. It can also run unswitched to an idiot light so you can see what's happening to battery charge in the daytime. I think I've stumbled into the truth there. We'll see what other guys say.

Whatever the case, ammeters are better than idiot lights, and 70's came with two batteries. If the L terminal is designed for 40's and 50's vintage cars running one old type battery -- trying to balance things out between night and day driving -- it doesn't really apply to your 70. So it ain't broke, and I'd advise against tying to fix it by messing with that L terminal

Steve