JD 50 starter mystery

This message is a reply to an archived post by mb58 on May 22, 2013 at 06:23:17.
The original subject was "JD 50 starter mystery".

Hello I was wanting to see if you ever found the culprit. I'm redoing a B and I've got the same issue. Starter works with jumper cable on post but when I put the switch on get nothing. I know it's making contact. Thanks if you can reply just curious. I've tried two switches I had neither works.

Neven

That didn't show up like I meant it to. There was an older post and I'm having the same issue with my starter. I've got it rebuilt by a company that does a lot of starters. It works great when I use cables from the battery and hit the copper button on the starter. But when I put my starter switch on which is making contact with the button I get nothing when I push on the starter lever. Not sure but I may have seen a little puff of smoke on the posative ground cable that was attatched to the starter frame. I tried another switch and looking at the insides it appears it's making contact. So I was curious if on the older post the gentleman figured out what the culprit was.

I've had the same problem and went and bought a new starter switch and it worked. What happens is when you tighten the nut on the top stud where the battery cable goes the stud will turn a little bit and it will not make connection . Those switches are bad about that after they get some age on them.

If you are seeing smoke, that is the place to be looking for trouble.

Take a look at the diagram below.



Note the terminal stud (Key 28) under the starter switch.

This terminal stud can get worn on one side and not make a good connection with the starter switch.

You might consider taking both the starter and new starter switch to the company that rebuilt the starter.

They should be able to rotate the terminal stud 180^o or install a new terminal stud.

Make sure the positive ground cable has a good ground connection.

Hope this helps.

The stud 28 is sloped on one side more then on the other and I will correct that and see if it makes a difference. I know the switch is making contact with it but maybe not enough.

If your switch and post are good sometimes you have to "tweek" the lever so it pushes it farther down.
You saw smoke at the switch ? Your switch housing may not be insulated properly ? The old switches used to have insulators you had to insert into the sides of the housing before mounting the switch on.

I will try it this weekend. The puff of smoke came from the posative clamp attatched to the starter housing (ground) not sure why.

Yes. The ground cable had a bad connection where it was bolted to the tractor. That was the whole problem and one I should have checked first!

Ok I'll move my ground connection too.

just try another switch don't just think its good can be new and still no good.

It could be several things, but the return spring on the switch could be binding up before actual contact can be made with both copper bolt heads. You can cheat the switch by elongating the mounting holes such that the actuating button sits closer to the copper bolt head on the starter. Likewise you can shim the battery cable attachment bolt to be further inside the switch housing so it too is a shorter contact path for the bar that connects the two copper bolt heads and closes the circuit.

To test, find a good ground point such as copper tube to oil gauge. Attach the ground lead of a simple test light to that and touch the point of the test light to the body of the starter while trying to start it. If it lights up, you have a ground problem at the starter mounting bolts, but it's rare that this is a problem. Should still be tested for since it's so easy to do.

Put the point of the test light on the battery connection at the starter and it should light up. Keeping it there, try to start it - if it goes out or very dim then you have a bad ground strap from battery to tractor chassis as the other guy had. Since it's easier to do the tests with a simple test light they should be done first just so you are not wasting your time on fixing a couple of good switches.

Just got done with the two switches I had as neither worked. They had contact on the copper lug just not enough. Once I moved things around it finally worked.