Electrical Gremlins ARGH!!!
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Topic: Electrical Gremlins ARGH!!!
Posted By: Sandknob
Subject: Electrical Gremlins ARGH!!!
Date Posted: 18 Mar 2010 at 11:15pm
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I am trying to repair the charging system on our 1960 D17. It still has the 12 volt gennie, but the battery was set up for neg ground (don't know if the gen was polarized when they put the battery in). The lights worked when we first got the tractor, but after my uncle put a new battery in they all quit working. Anyway, the battery will not stay charged up and if the cables are left hooked up it will drain the battery. Battery is shot at the moment so we have to buy a new one of those anyway so that takes care of that end. I am stuck on the voltage regulator and the gennie right now though. Where do I start looking for the problem? How do I test the generator? How about the voltage regulator (going to guess it is original)? Also I would like to convert it "correctly" to negative ground. How do I go about converting it (polarizing generator, etc).
Thanks
Adam
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Replies:
Posted By: JC-WI
Date Posted: 19 Mar 2010 at 12:33am
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Sandknob, First thing I would do is to buy a new regulator if you are staying with the generator. - There are people that tell me there is NO differenc between negative and positive polarity regulators, I beg to differ since I remember putting new regulators on that would be stamped with either "pos ground" or "neg ground". Maybe the new regulators will work with either system, but I do not know that answer.
- If I Remember right, Generators can be polarized either way and to do that, after everything is hooked up correctly, you take a jumper wire and momentarily touch BAT terminal on the regulator to the GEN or ARM terminal on regulator and then your done.
For me, if the regulator is toast, I will decide its time to put an alternator on the tractor instead. But if some cleaning of points in reg. solves the problem, I would just clean it up and leave it that way. I would also check generator and replace brushes , bearings and true the commutator.
- Unless I needed to update to 12Volts Neg. ground system for something that uses lots of electricity then big amp alternator gets tossed on.
Say like the WD45 that I use quite a bit at night, Got 5 Halogin lights on it. A generator wouldn't keep up. Really kind of neat cultivating corn with those lights. Got no problems handling an electric pump for spraying either.
Battery draining - sounds like a contact is stuck in regulator.
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Posted By: Butch(OH)
Date Posted: 19 Mar 2010 at 5:12am
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I think you are on the right track, classic symtoms of reverse polorazation, usualy from bass-ackwards jumper cable hook ups or somebody put a battery in with wrong ground polarity. What happens is the cut out relay points get welded together from hi current and then when you shut it off the generator is trying to motor and drains the battery. The check for this is easy, loossen the belt or best remove it and put the cables on your new battery. If the generator motors, or trys to motor you have regulator problems. I made plenty of pocket money "fixing" E Gleaners that the owners thought were electricaly posessed when all that was wrong was they messed up the polarity by jumping them backwards. " it only charges when I run the headlights???? was a classic line. If I was busy Id tell them, heck just shut it off and leave the headlights on for 20 minutes, that outa charge the battery up enough to keep it going 'till I get there to fix it, LOL. Yes regulators used to be polarity specific but now at least some of them are universal. They did this by changing the ground paths for the points. |
Posted By: jaybmiller
Date Posted: 19 Mar 2010 at 6:28am
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As other's have said..sounds like a botched rewiring and a bad regulator. Satrt fresh with good new parts and you should be good for another 50 years!
However, I'd like to see a 'polarity specific' regulator's guts,Unless it has diodes in it,I can't see how it could be polarity specific. Regulators are nothing more than 'fancy' relays and I've got over 50 years of playing with them.
curious Jay
------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: Butch(OH)
Date Posted: 19 Mar 2010 at 7:23am
Here a link to service bulletin 1R-116 look at page 4. I have an original in the shop that keep handy. It is a good read for all you guys trying to learn about your old Delco charging systems. It does not apply to Autolite beacuse of differances in how the field is controlled.
http://www.ruiter.ca/mc/info/PDFs/1R-116.pdf - http://www.ruiter.ca/mc/info/PDFs/1R-116.pdf
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jaybmiller wrote:Posted By: Jim Lindemood
Date Posted: 19 Mar 2010 at 8:16am
| Sandknob - I have similar problem on a D17D II. Electical systems to me are one of those "mysteries of life". Question, If you put jumper cables on battery, does the tractor start and run OK? Mine does, but seems to drain the battery after shut off and if it sits overnight, won't start. For those experts, does this sound like reverse polarity, or just bad regulator, or generator? |
Posted By: Dave(inMA)
Date Posted: 19 Mar 2010 at 8:47am
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That bulletin is a great reference. Thanks, Butch. ------------- WC, CA, D14, WD45 |
Posted By: Gerald J.
Date Posted: 19 Mar 2010 at 10:02am
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Its conceivable a voltage regulator could have a permanent magnet in the voltage sensing coil. That would make it polarity sensitive. I think the big difference in a polarity sensitive regulator is that those contacts use different metals for cheaper construction and decent longevity and running it reversed seriously shortens the contact life. A generator putting out the wrong polarity will try to smoke charging a battery and could do a welding job on the cutout contacts in the regulator. Taking the fan belt off and checking for motoring is a good test. The battery posts and connectors were made fat and thin to HINT at proper polarity. Usually the fat connector rattles on the thin post and the thin connector won't go on the fat post, but a file and hammer can force those things. To change polarity, you need to swap the cables so the connectors fit the battery posts for future reference. You ought to put a sign, saying "Converted to negative ground." You need to swap the connections at the ignition coil primary, putting + to power, - to points, and you need to swap the connections at the ammeter putting - to battery. Yesterday I found some SAE history I'd been looking for. SAE standard J538a was new in 1955, revised in 1963 and reaffirmed in 1973 according to the 1980 version I have. I suspect the 1955 version required the grounded post of the battery be grounded well so the voltage drop the starter was small meeting J541a. I suspect the revision in 1963 was to get to the 1980 wording the requires the NEGATIVE terminal of the battery be securely grounded. Deere was still building positive grounded gas tractors in 1968 so it didn't have an immediate effect. Gerald J. |
Posted By: Steve in NJ
Date Posted: 19 Mar 2010 at 11:17am
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The first thing to do is bring your Gennie and regulator to your local rebuilder and have him run some tests on both units. While he has those, head back and run through the Tractors wiring, cables, do a Battery test, and make sure there isn't any open circuitry or old chaffed wiring that could cause a multitude of problems later when you get your Gennie and VR back. Whether your Gennie and regulator combo are good or bad, at least you can run through things on your end and make sure the rest of the system is going to function properly. A VR is always an easy thing to point a finger at, but it isn't always the problem. Grounds, grounds, grounds! Make sure the grounds are good throughout the electrical system. Mother Nature plays havoc with electrical connections, and grounds especially on old Tractors that are out in the elements. Add age to the equation, and you have lottsa' things that could go wrong. Keep us informed on how you make out....
mailto:Steve@B&B - Steve@B&B
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Posted By: ALinIL
Date Posted: 19 Mar 2010 at 12:18pm
| Steve - Points well taken. On older tractors, I have found that the ground system is a major cause of electrical problems. I always rewire since the wiring is usually about 50 years old. The insulation frays and gets brittle, wires also fatigue and break. This can lead to intermitten problems. I also always run an extra ground wire to ground the regulator,battery and Gen. This assures you have a ground. - AL |
Posted By: john(MI)
Date Posted: 19 Mar 2010 at 12:30pm
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Butch, Thanks for the book. ------------- D14, D17, 5020, 612H, CASE 446 |
Posted By: Brian Jasper co. Ia
Date Posted: 19 Mar 2010 at 3:09pm
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Adam, you can test your generator by removing the fan belt and wires and run whichever polarity your tractor is using as the "hot" side to the "A" post on the generator. The generator should spin like a motor. While it is motoring, ground the "F" terminal on the generator. It should slow down, but continue to spin. If it does this, your generator is ok. Check the wires between the generator and regulator. I use a headlight bulb. If the wires will conduct enough current to light the bulb, they are ok. Don't overlook rusty/loose connections. If all tests good, replace the regulator. From what you describe, sounds like the cutout relay contacts are stuck together in the regulator.
Regulators used to be always marked POS or NEG ground. The regulators that places like Valu-Bilt are typically "Universal" ground. They're ok for a collector tractor that only sees a few hours each year. If you plan on using the tractor like it was meant for, they typically don't last long. Last I knew, Borg-Warner was the only domestic company making a quality generator regulator any more. I haven't had to replace a generator regulator for many years so it may be tough to find a B.W. unit. ------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford |
Posted By: jaybmiller
Date Posted: 19 Mar 2010 at 7:26pm
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Hay Butch, Thanks for the info.While page 4 talks about polarity ,there ain't no pictures of the guts, as to WHAT makes them 'sensitive' .That's what I'd like to see. Heck, regulators are nothing more than 1 to 3 relays in one box. Take a standard 'automotive 30Amp relay'. Two wires go to the coil.Doesn't matter which one goes to the +12, it'll always turn on.Flip the wires and it'll still turn on.... As for the 'points' having more material on one side, I'll lay odds that ain't true today.I've used thosands of relays in industrial applications,all have same points on them.
I'm just curious, like my cat...
...and still young enough to learn.
Jay
------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: Butch(OH)
Date Posted: 19 Mar 2010 at 8:05pm
| I dont mess with generators enough anymore to remeber the details on the uni regulators but it comes to me on the one I used that the regulator body was isolated to ground and it had a jumper you attached one place for positve ground and to the mounting tabs for negative ground, I may be off on that so dont hold me to task but there was an external jumper to switch it. It is under the fuel tank of our A#2 and hard to look at. I cant even begin to answer the whys, I just know a person cant just switch grounds and get away with it for long. As I was taught and per the manuals it will eatthe point up in short order. |
Posted By: Chalmersbob
Date Posted: 19 Mar 2010 at 8:48pm
| Remove the regulator and look on the bottom to see if it is marked for voltage and polarity. If you have a generator, the tractor should be positive ground. If you say a new battery was installed and the lights haven't worked since, it is possible a 12 volt battery was installed into a 6 volt system and th bulbs all blew. Like Steve said, check the wires and grounds. Bob |
Posted By: Gerald J.
Date Posted: 19 Mar 2010 at 9:31pm
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Jayb, trouble with your relay analogy is that the relay operates fast at 1 or 2 cycles per second in most applications and pulls in at probably 8 volts and drops out at 5 when rated for 12 volt operation. The VR buzzes at 14.2 volts breaking an inductive field coil circuit. Its only protection is the fixed resistor that sets the minimum (and starting) field current. The inductive field circuit is easy to close on and the current rises relatively slowly, but on opening the current wants to continue so develops high voltage to supply the arc. That's when the VR points burn. And its always the same polarity arc. The relay points also have maximized contact pressure while the VR contacts are on the verge of opening so have low contact pressure. If both points on the VR were made of the best material (likely tungsten based much like ignition points where the condenser evens up the arc erosion) the VR would be insensitive to polarity affecting its life, but remember the annual production of tractors, cars and trucks in those days probably ran a couple million units in voltage regulators and if an engineer could save a penny a unit on contact material in the voltage regulator, he just paid his salary and overhead for a year or three or more. Gerald J. |
Posted By: jaybmiller
Date Posted: 20 Mar 2010 at 6:23am
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HAY Gerald, great info on the points polarity issue.Makes me wonder why they don't have arc supression capacitors in the VR units(probably $$$ saved ?). Anyway, when 'they' talk about polarity, 'they' are referring to the points and NOT the coils inside the units, after all the coils don't care about polarity,they'll pullin either way.
Jay ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |