1948 A Starter

DougJD48A

Member
I posted earlier about starting issues with my 1948 John Deere A. I replaced both battery cables, pulled the started and cleaned all connections to the starter
switch itself. The starter weakly turned over for maybe 30 seconds then ultimately stopped. I also thought I heard a little popping sound. Now the starter
doesn't do anything even with a charged battery. My guess is the starter switch has gone out or the starter itself needs to be rebuilt. Is it best to start by
replacing the switch first? If I need to rebuild/replace the starter, what are the options? Who sells starters or rebuild kits? I really appreciate all the
help. Thanks,

Doug
 
Often the copper washer/contactors inside those mechanical push down starter switches get burned pitted and corroded causing failure or else the external copper contact post on the starter itself (what switch contacts with) gets the same. Another problem can be the ground cable connection if its to any thin wimpy rusted sheet metal like the battery box or seat frame is the cause. Try grounding to a good clean shiny heavy frame component instead of sheet metal. Had you not replaced the cables I would have advised to remove clean n wire brush each and every battery and ground and starter switch connection. If its NONE of the above (starter switch or ground or cables or connections) and the battery is good sure it can be the starter, but its more often a connection or switch or ground problem or battery. Sure its good and full charged ??? One other problem I saw was the push down button on the switch wasn't getting pushed down far and hard enough due to a linkage problem, that needs pushed down far and tight enough to work right.

That popping sound reminds me of a cable or connection or ground issue, remove clean n wire brush all of them.

John T
 
Great advice from the last post, the starter switch very well could be your issue, I had to jb weld a couple of nickels on the button to get it to go down far enough on my 50, good luck
 
I have a battery in a tractor I?m working that has 13 volts on the volt meter but when you hook it to a carbon pile resistor it won?t even give 50 amps
 
Thanks to everyone for the responses. I really appreciate the collective knowledge of this group. The battery positive is grounded to the main frame just below the battery box. I replaced that cable and ground the spot on the frame down to shiny metal before re-attaching. Good point about the battery. The battery was bought in 2016 so I will replace that just to be sure. I will also replace the starter switch and look at the travel of the actual starter rod. To my knowledge that starter rod is original and not bent so that should not be the issue, but I will certainly check.

Thanks again,

Doug
 
At this point its time to remove the starter and bench test it. This will isolate the problem to the starter if it has one. Remove the switch and contact the stud (with pos cable) directly with battery. Neg cable to starter case.
 
A no load bench test really doesn't do much as even a bad starter will spin up to speed with no load on it. Take the starter apart & pay attention to the bushings & brush wear.
 
Thanks. I will do that. Just so I am clear, wouldn't the negative go to the stud under the starter switch and the positive go to the starter case since this tractor has a positive ground?

Thanks,

Doug
 
Yep on the positive grounded tractor + is to starters case/frame and - to starter post HOWEVER it makes no difference and will still turn the same direction. It should spin fast and smooth and even with no dragging or growling or screeching HOWEVER that's a no load test and it can still be bad even if it spins good on the bench.

John T
 
Thanks for the clarification. If I do a bench test and it spins I at least know that the switch was bad because it will not spin now mounted on the tractor.

Thanks,

Doug
 
Hey that's a good point also, no spin at all with switch versus spin if by passed sure tells you something !!!!

John T
 
You are correct John T a load test is best, even after a bench test. But if its not spinning on the tractor and all connections are good what would the next step be? Forgot to mention I do have a growler.
 
Darn if I know lol. If EITHER using the starter switch PLUS direct (by passing switch direct to button contact on side of starter under switch) CONNECTING BOTH makes it spin on the bench but it wont turn the tractor engine over...??..I still wonder about the switch contact to the starter button (carbon or pitting or burning) but if that's not it and allllllllll grounds and connections and the battery is good ??????? The starter itself is sort of what's left ??? Id also have the battery load tested as even if it shows a full charge of 12.6 volts it can still fail under load

John T
 
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