Voltage Regulator keeps Failing

Sun Nov 11, 2012 4:27 pm

I have a 1957 Lowboy, and have been going thru a new NAPA Voltage Regulator about every 2 - 3 years, and another just failed. Is there something that I need to check that could be causing this. Is there a better regulator that someone would recommend? BTW, it's 6 volt.

Re: Voltage Regulator keeps Failing

Sun Nov 11, 2012 6:09 pm

It depends on which voltage regulator you have been buying and how you use your tractor. The $40 India made one does not last as long as the $70 USA made one. It has to do with the quality of the contacts inside. I am of the belief that only one company makes the USA made one and is sold by multiple vendors. The NAPA part for the USA made one is VR851. The more you use your Cub, usually the less trouble with the regulator contacts. This is because the arc created during operation tends to burn off corrosion on the contacts. If there is too much corrosion, no arc is made. I chose to go the route of an electronic regulator. Here is my write up. http://www.farmallcub.com/phpBB2/viewtopic.php?f=1&t=71175 It is not cheap, but I will say I am happy so far. I have had it less than a year, so long term reliability is not known. What I really like is that it settles down much faster than the mechanical regulator and there are no contacts inside. Yet another route is to convert to a 12 volt alternator. Those are pretty much your options. --Lee

Re: Voltage Regulator keeps Failing

Sun Nov 11, 2012 6:13 pm

Well I am not familiar with the NAPA regulators, but I do know that NAPA has two levels of products. One the isn't top notch and one that is much better. And the much better one costs more than the not so much top notch. When it comes to regulators, cut-outs, generators and starters I take all of that to my local AC Delco Service Centre where I know they repair them properly and all replacement parts are high quality. It has been a couple years since I had my cut-out replaced and I am very happy with it - here is the thread - Generator and Cut-Out

Re: Voltage Regulator keeps Failing

Mon Nov 12, 2012 9:22 am

Interesting that LeeC continues to be pleased with the electronic regulator. The alternators with internal regulators have electronic regulators too. Given the time involved in going to get another electromechanical regulator and install it, and the reported short service life, the electronic price seems not so bad if it proves durable.

Looking back at the new cars of my experience, a 1950 Chevrolet owned for two years, a 1952 Chevrolet owned for 6 years, both 6 volt negative ground, a 1958 Chevrolet owned for 5 years, 12 volt generator with negative ground-- none of them ever had a voltage regulator problem. A 1972 Chevrolet and a 1980 Mazda, both alternators with external regulators, developed problems with excess voltage. The Mazda was feeding over 18 volts to the battery and bulged the battery casing.

Re: Voltage Regulator keeps Failing

Mon Nov 12, 2012 12:20 pm

Have you taken it apart and checked the air gaps? I was also going through regulators at about that rate, but fortunately, I saved my old ones. When the last one died, I decided to pull it apart and check the gap. It was out of spec, and after I adjusted it, Eddie was charging her battery again. The others were also out of spec, so I adjusted them as well. I swapped the first one I adjusted out for another, and it works as well. Have not tried the third yet. However, it's been nearly a year since I put the second adjusted one in, and (touch wood) she's still charging.

FWIW, I have bought both the expensive and not-so-expensive (but still not cheap) NAPA VRs, and they each lasted about the same length of time.

Re: Voltage Regulator keeps Failing

Mon Nov 12, 2012 4:41 pm

I am going through this right now with my Ford 3000. Not a cub, but same problem. My rebuilder, who has 35-40 years experience, worked with a VR that he sold me 3-4 years ago for over an hour trying to adjust it. This particular one has a thin washer which is riveted in place. This acts as a cam to raise or lower the points. The washer is riveted so tightly that it cannot be moved for adjustment. The output goes from 12 volts to 18 volts, with nothing in between. There is no way to fine tune it.

I still have my old Ford VR, which I installed back on the tractor. It works better than the "new" one. My readings are in the 14-16 volt range. This one has the springs that hang down from the tabs on the points, which could perhaps be tweaked. The ammeter looks about normal, but with a lot of excited motion of the hand. Before I buy another VR and go through the ordeal of finding a good one, I plan to take the genny and original VR back to the rebuilder to see if he can adjust it closer. Right now I could use as it, but I don't want to damage my battery or my newly rebuilt genny.

By the way, the reason for struggling with the genny and VR instead of changing over to a one wire, is I will lose the tach drive on the rear of the old genny.

Re: Voltage Regulator keeps Failing

Mon Nov 12, 2012 9:03 pm

Machineryman; A bad connection some where in the system can raise heck with a regulator. It could be hot or a ground problem, either one can cause a problem. Generally though, a connection problem wouldn't take 2 to 3 years to cause a regulator to fail.

Re: Voltage Regulator keeps Failing

Mon Nov 12, 2012 11:33 pm

Gee why did I ever go with a single wire alternator and get away from this dirty contacts, corroded contacts or who knows contacts. The big guys made the change and still do it that way. Even the new Case Tractors. I personally am not that much of a purist that I will repeatedly shoot my self in the foot. Of course if it is working OK leave it alone, But if ETC

Re: Voltage Regulator keeps Failing

Fri Nov 23, 2012 5:59 pm

Does anyone know the "gap" or "space" settings on the "side mount" voltage regulator? I would like to check the settings to see if that is really the problem.

Re: Voltage Regulator keeps Failing

Fri Nov 23, 2012 6:33 pm

Please describe your problem in detail. Do not start adjusting until we try to troubleshoot the problem. Does your ammeter show a charge? If there is a charge, is the amperage to high? or too low? or erradatic? Have you worked on any part of the electrical system recently? If so, please describe.

Re: Voltage Regulator keeps Failing

Fri Nov 23, 2012 10:11 pm

Charging system totally dead. No thing from generator. Done this before and it was fixed after replacing regulator. Do you have the specs for the regulator so that I can check them?

Re: Voltage Regulator keeps Failing

Fri Nov 23, 2012 10:24 pm

Regulator specifications are located in section 8 of the service manual. But you need to know the appropriate Delco part number for the regulator. Or the specifications for the current make/model replacement regulator.

Re: Voltage Regulator keeps Failing

Fri Nov 23, 2012 10:51 pm

The specs for the original regulator are on page 13 of this manual. Description of the tests and adjustments start on page 20. Unfortunately, I don't know how applicable those specs may be to whatever replacement regulator you have now.
This was published in '55 and I think it still was current in '57.

Re: Voltage Regulator keeps Failing

Sat Nov 24, 2012 8:31 am

Thanks Jim. See that you are up early today. Do you still have your Low Boy?

Bob C. in Virginia

Re: Voltage Regulator keeps Failing

Sat Nov 24, 2012 11:04 am

It was still last night here when I made that post, whether it should have been or not. I still have the LoBoy. Things arrive here every so often but very few leave.