Farmall Cub

Hi, I replaced the wiring harness on my super A, also coverted it from a 6v positive ground to 12 v neg. ground. Replaced the voltage reg., coil with internal resistor, had gen. reworked to correct voltage and changed battery. This worked like a charm it cranked and ran very well also charged correctly (just shy of 15 v.) all of a sudden, without warning, it shut off just like you turned off the switch and has not hit a lick since. I have voltage going to the coil + side but none on the - side going to the dist. Also the coil got so hot it could not be touched so i replaced it with another coil (2 actually) and still no fire to dist. ? Anybody else ever had this problem?

check your condenser and the post going inside the distributor for shorts. The i side of the coil going to the distributor should have voltage when the points open, but none when they close. If something is shorted the continuous current flow will cause the coil will get hot. In normal operation it only handles short bursts of current.

Thanks, I will try that.Earlier today a friend and I discussed that, my thinking was, voltage has to go through the coil to get to the condenser which lead me to believe it was the coil. Am I correct in the attachment on the wires to the coil? + side from switch, - to dist. If I remember correctly, this was opposite when it was 6 v. pos. grd. Thanks, Brian.

yes, that is correct for - ground.

I agree with John, if you have the same "no voltage" condition with multiple coils, there's a short of some sort in the dist.

my 140 did the same thing just a couple of weeks ago. my coil was also hot , i bought a new one ,same thing no start. i checked the fuse in the dash and it was blown. i changed it and bam it started right up!

I also had a similar problem with my SA the first time I tried starting it after the restoration and new wiring harness. Turned out the edge of the condenser wire connector at the terminal post inside the distributor was just barely touching the wall of the distributor. I took a small screwdriver and pried it away and it work perfectly! I was also prepared to replace the insulator around the post on the side of the distributor where the coil wire attaches, but didn't need to at that point.

Gary Dotson wrote:I agree with John, if you have the same "no voltage" condition with multiple coils, there's a short of some sort in the dist.

And Gary. Problem is an electrical short from the coil to and including the distributor. Most likely inside the distributor.

My first thought, since tractor ran for a while, is that the screw holding the points' bracket into positon loosened - causing the points to remain close.

Next possible that the points spring slipped and is shorting to the distributor case. Or the insulator through the distributor case has slipped out or is broken.

Could be a couple of other distributor related problems. Distributor drive broken, etc.. Check the easy stuff first.

We checked the points and spring, condenser wire and all seemed fine. Insulator through dist. is good, nothing touching metal that should'nt be. At this point would yall replace the condenser and see what happens ? Also, if I had the wires going to the coil attached like it was when its was pos. ground, ( wire from switch to - side and wire going to dist. to + side of coil ) would it still crank? If so, this might be the way it was attached before this problem. I realize now it should be reversed. Thanks in advance guys, and sorry for so many questions I am having to learning as I go.

At this point, disconnect the condenser lead, rotate the engine to the point where the points are open and check again for current at the dist. side of the coil, it should be present. If so, replace the condenser, if not, you've missed something.
The ignition system will function with coil connected either way, but will work best when connected properly. Connect it with the neg. to the distributor and move on.

Changed condenser Sat. hit the starter, it cranked up and ran smooth as could be.Don't know what would cause a near new condenser to go bad? Maybe something to do with the coil hooked up backwards? but all seems fine now. Thanks for all the help guys.

Goodoldreb wrote:Don't know what would cause a near new condenser to go bad?

Take a look at the box and see where it was made. That should give you some insight.

You know your right. Just happened to remember, I had a M1 Garand made by International Harvester, reckon who it was being used on in 1952 (yr. my Super A was built)? Now I have their parts on my tractor!

I've always found that the chances of a new condenser being defective is greater than the chances of the old one failing. I'm not sure why we think we need to replace a perfectly good condenser when we replace points, it's just always been the practice, I guess.