[Scott 1234]

Morning. I have a 1966 cub lo boy. I bought 2 years ago , now as a retiree. since it was what I had as a boy on our farm. Ran generally ok (fixed a couple of things on it each season) . Now when I tried it this month (to make sure battery is ok etx ). It won’t start. Battery turns it over fine . I thought maybe carb issue. Since I had problems with that last season going up hills. (It would conked out). But sun jn law suggested first check the electrical. So he lent me that spark tester thing that plugs into plug and should light up if there is a spark. and looks like no spark at any plug .nothing lights up As an armature. What do and how do I test next few steps ? Or just start replacing stuff (I saw you tube on replacing points and such. And that all scares me - I’ll mess that up for sure So just by replacements something instead ??)). I’ll try here to give some pictures. Of tractor. The tester that didn’t light up when I tested the plugs.(guess I don’t have a pic of that. You know what I mean I’m sure ) And the electrical parts . Thanks ! For any good advice for a handy guy who normally doesn’t have his repairs go as planned ever .

 

[LouNY]

Your points are the first thing.

 

[I use red mn]

You need to obtain a 6-12 volt circuit tester, see link for example. Auto parts stores should carry them. First you need to test for power with the switch in the on position on the terminal of the coil that is OPPOSITE of the one that has the short wire shown in the 3rd picture between the coil and distributor. Then on that short wire you need to test for power at either end of it when the points open and then no power when the points are closed. This may require filing, sanding the points contacts or actual replacement. The statement you made about just replacing the points which can be done but also requires them to be set at 0.020” by using a feeler gauge no matter if that are new or used. The terminal for the short wire coming out of the distributor should flash on and off when the engine is cranking and then ignition is on. If this is happening you should have spark as well. Testing the generator and charging system will all come after you have it running.
Example test light

 

[Scott 1234]

You need to obtain a 6-12 volt circuit tester, see link for example. Auto parts stores should carry them. First you need to test for power with the switch in the on position on the terminal of the coil that is OPPOSITE of the one that has the short wire shown in the 3rd picture between the coil and distributor. Then on that short wire you need to test for power at either end of it when the points open and then no power when the points are closed. This may require filing, sanding the points contacts or actual replacement. The statement you made about just replacing the points which can be done but also requires them to be set at 0.020” by using a feeler gauge no matter if that are new or used. The terminal for the short wire coming out of the distributor should flash on and off when the engine is cranking and then ignition is on. If this is happening you should have spark as well. Testing the generator and charging system will all come after you have it running.
Example test light

Thanks. Ok. Forgive my total ignorance on your step one. 😟. So I got a tester as suggested (Fran barn. Looks like it still works as it lights when I attach to battery and ground if ). Ok. So I turned the key on position. I hook th r tester wire aligator clip to a ground ? And

the other end to the coil . And I get nothing No light. Did I mess up already in my testing. ? Was the aligstor clint supposed to go elsewhere then a ground ?

 

[LouNY]

Nope a good ground and you should have gotten power at that point. Even if the points were closed I would have expected the light to at least be on dimly.
You can disconnect that wire from the coil and then check for voltage again, also the key was turned on correct.

 

[LouNY]

Are you using the same ground that you checked the light with.

 

[I use red mn]

Yes, clamp the alligator clip to a ground. A good spot would be to the galvanized steel clamp around the coil. Should be able to clip it by the bolt and screw at the base of it. Check again. If no power is showing as Lou is suggesting it is a good practice to verify your light works and you have a proper ground. Do this by reaching over to the battery cable terminal on the starter and touch it to make sure the light shows power there, If so go back to the coil terminal and recheck. If you still see no power there you have a problem with the ignition switch or the wire feeding the ignition.

 

[HydroTek]

Rusty tip on that light -- use some sand paper or a file to "freshen up" the point on the probe -- and be sure the clip is on a good ground

You should have power on that terminal in your pic with the key on
and the test light should flash, when cranking, with the tester on the other coil terminal -- this tests the points

Do yourself a favor and change out the points for a Pertronix kit

 

[Scott 1234]

Thanks all (what a great group of experts I have found ! Thanks ). Ok after it warms up outside I’ll go double check BUT I can Tell you this much - the ground was a clean bolt - and when I used it and touched the positive side of the battery with the tip I got a Bright light 💡 (so to me that tells me my grounding was probably good with the tester ) right ? I also then tested the other connector on the other side of it (where Yiu see the short wire ) and likewise - nothing 😟. No light 💡. Oh and yes - I tested with key on and with key off - nothing but .nope. Was not cranking it as same time however. But I will recheck and let you know . Thanks

 

[Scott 1234]

Thanks all (what a great group of experts I have found ! Thanks ). Ok after it warms up outside I’ll go double check BUT I can Tell you this much - the ground was a clean bolt - and when I used it and touched the positive side of the battery with the tip I got a Bright light 💡 (so to me that tells me my grounding was probably good with the tester ) right ? I also then tested the other connector on the other side of it (where Yiu see the short wire ) and likewise - nothing 😟. No light 💡. Oh and yes - I tested with key on and with key off - nothing but .nope. Was not cranking it as same time however. But I will recheck and let you know . Thanks

 

[Scott 1234]

Praise God. ! You solved it ! And it was so so simple ! I rechecked it. No light. Went back to the starter switch key. . Looked fine. all wired fine . But I then ever so slightly pushed the one wire lead on a tiny bit tighter. (It was on. Just a micro bit back) and I Tried it. And … it starts !! That gives you a good feeling to hear it turn over and on. 😀. Thanks all !!

 

[I use red mn]

I had typed up a reply and somehow did not hit the post button, it will follow.
Glad to hear you found the problem and thank you for being appreciative of the help. Apparently these tractors have a key switch with plug on wires or someone changed the switch. I would recommend that you unplug the wires from the switch and check out the connections there to make sure they are clean, not corroded and tight. Otherwise it might cause a problem at some inconvenient moment in the future.
Here is the post I meant to add, it is more about proper use of a test light.
…Yes, clamp the alligator clip to a ground. A good spot would be to the galvanized steel clamp around the coil. Should be able to clip it by the bolt and screw at the base of it. Check again. If no power is showing as Lou is suggesting it is a good practice to verify your light works and you have a proper ground. Do this by reaching over to the battery cable terminal on the starter and touch it to make sure the light shows power there, If so go back to the coil terminal and recheck.

 

[Scott 1234]

I had typed up a reply and somehow did not hit the post button, it will follow.
Glad to hear you found the problem and thank you for being appreciative of the help. Apparently these tractors have a key switch with plug on wires or someone changed the switch. I would recommend that you unplug the wires from the switch and check out the connections there to make sure they are clean, not corroded and tight. Otherwise it might cause a problem at some inconvenient moment in the future.
Here is the post I meant to add, it is more about proper use of a test light.
…Yes, clamp the alligator clip to a ground. A good spot would be to the galvanized steel clamp around the coil. Should be able to clip it by the bolt and screw at the base of it. Check again. If no power is showing as Lou is suggesting it is a good practice to verify your light works and you have a proper ground. Do this by reaching over to the battery cable terminal on the starter and touch it to make sure the light shows power there, If so go back to the coil terminal and recheck.

Thanks again. Once I grease the tractor up (my original winter project). I’ll take it for a full run up our hills. I am wondering now if this electric issue was part of the problem I had last fall - I mowed the fields. Fine. Went up our steep Xmas tree hill : it conks out. Someone back then suggested. Back then. That was a carb issue - (Ie. Float getting stuck as I go up steep incline). Maybe it was just that simple connection coming loose ! (I’ll be calling on you for carb help if it conks out again going up a steep incline. and so that is not an electrical issue 😣). We shall see …

 

[HydroTek]

The plug in switch was factory -- same as the cub cadet mowers with the generator start
IH used to sell a bendix starter upgrade kit -- I have installed a lot of those

use Ox-Off electrical grease on the terminals of that switch
you can get the grease at the hardware store or electrical supply house -- GB is one brand

 

[Scott 1234]

Grease : Ok. My new son in law is an electrician. I’ll get that grease from him 🙂. And give a try on the connections to key switch (of course if you know these 1966 low boys. They make it hard to reach into anything easily ) thanks much !