Farmall Cub Won't Crank

[jrgkribel22]

I'm relatively inexperienced working with tractors so I'll try to explain my problem and what I've done the best I can.

I have a 1967 farmall cub lo-boy, 12 volt positive ground (I know it should be a negative ground but I had someone work on it years ago and he rewired it to positive and that's how it's been). In February the clutch release bearing failed and I parked it and let it sit until October...it was outside and not covered, yes this was stupid. I had a friend help me push it into the barn and split it to replace the release bearing and that all seems to be good to go. However, I cannot get it to start. It won't crank, it won't try to turn at all. Here's what I've done, some on my own and some after reading posts here:

1. Replaced the battery, all instruments/switches in the dash panel (except for the fuse holder), spark plugs, the starter coil and the voltage regulator. Cleaned the ends of all the wires to make sure they were all bare connections.

2. I've put the tractor in 3rd gear (battery disconnected) and rocked it back and forth...fan blade moves quite a bit when I do this.

3. Taken the starter off and verified that it spins, which it does.

4. taken a multimeter (this is the first time I've ever used one) and tried to see if I get power to various places...I get 12 volts when I touch the leads to the + side on the battery and the nut on the starter (as well as on the bolt mounting it to the frame, which I'm guessing means it has a good ground?), and I get negative 12 volts when I touch the leads to the - side on the battery and the starter switch (this has a key switch then a push button to start, I'm touching the back of the push button on the side that is connected to the cable running to the negative battery terminal).

I'm at a complete loss as to what is going on. Also, don't know if it matters, but when I charged the old battery, and then the first time I had the new battery connected, just when I first pushed the starter button I heard a tiny almost click sound and then nothing. I haven't heard this sound any other time.

Thank you to anyone who has any suggestions!

[CharlieK]

ck all your grounds

[staninlowerAL]

Welcome to the FORUM. One more post and you can access/download the Owners/Operators/Parts/Service manuals from the Quick links tab at the top left corner of this page. Does your push button connect to a solenoid or directly to the starter? Connect a jumper from the battery "hot" post directly to the starter to verify that the push button switch is making contact. If the starter will motor with the jumper cable and turn the engine, you might have a bad push button starter switch.
EDIT: What is your Loboy serial number? The above comment is based on the assumption that the push button starter switch cables being connected to the "hot" battery post on one side and the starting motor on the other side. This switch/cable assembly is detailed in TC37F Parts manual page 71 which shows the dash mounted push button start switch #376 295 R91 Illis. #4, battery to switch cable Illis. #2 and switch to starter Illis. #30.

[Dale Finch]

.... (this has a key switch then a push button to start, I'm touching the back of the push button on the side that is connected to the cable running to the negative battery terminal)......

I believe this means you don't have the saddle starter switch. Is there a solenoid somewhere? On the starter or somewhere else?

Also, confirm that the engine does freely turn.

[Matt Kirsch]

I've got the same year Cub, my first Cub in fact.

It has a big push button on the dash. Think saddle switch, but mounted in the dash.

Mine's a little finicky sometimes. If I give it a few sharp jabs with my palm that usually breaks through the carbon and it works again.

Those switches are famous for getting all carboned up and not making contact.

Bypass the switch with a jumper cable direct from the + on the battery to the terminal on the starter. It will arc and spark but if you aren't timid about it and just go for it, I bet the starter will turn.

That will tell you either the big switch is bad or one of the connections/cables is.

[jrgkribel22]

Thank you for the welcome. And thanks for the information about the link to the manuals, I have paper copies of all of them. And sorry, it took me a while to get back to the tractor.

I do have the saddle switch, like Matt said in the dash. I've lost the serial number as I had to replace the lower radiator housing years ago and I lost the tag in the process, but I do remember that it was a 1967 lo-boy when I looked the tag number up before I lost it (it's not a 154 or any of those similar ones, it's a plain lo-boy). The connections go from the hot side of the battery to that saddle switch, then another cable from that switch directly to the starter.

I've put the tractor in 3rd gear and rocked it back and forth...when I do that I see the fan moving about a 1/4 turn around a full rotation back and forth (so one blade moves back and forth between horizontal to the right and then vertical pointing down), is this enough movement to confirm that the engine is free?

I have put in a new saddle switch, ammeter, light switch, key switch, voltage regulator, and starter coil. All the wiring is less than 8 years old, and I've cleaned all the ends of the wires.

I tried connecting a jumper cable to the hot (in my case negative...like I said I know my model and year should be a negative ground but I had someone do work on it about 8 years ago and they rewired it to be 12V positive ground) battery terminal and to the post on the starter. When I did this the first time I saw a very faint orange spark at the starter post but nothing turned, I didn't see any arcing. I tried touching the jumper cable in the same way a few more times and I saw no spark and the starter did not turn. I checked the battery with my charger after this and the battery appears to be fully charged.

So does this mean that I have a bad starter?

[staninlowerAL]

Probably so. You can remove the starter from the engine and see if it will "motor" with jumper cables. Maybe have the starter checked by a RR shop, you could have a bad armature.

[jrgkribel22]

My apologies, but what is an RR shop?

[phill_mi]

A shop that repairs or rebuilds starters near you.

[SONNY]

take heavy jumper cables and hook them DIRECT to the starter itself! This will bypass all wiring on the tractor. Hit the "hot" end to the starter post hard,---IF the motor turns over then you have wiring/switch problem. I have started them in an emergency this way but I dont recommend anyone else do it ! This is ONLY a test to verify that your starter is good!

[jrgkribel22]

Oh ok, thanks, I might know a place that does that near me.

As for the jumper cables, I had heavy gauge jumper cables and connected one end to the hot on the battery and the other directly to the post on the starter. I didn't hit it hard but I can try that. Also I didn't have the other jumper cable connected to anything, so I just used one cable (I used the black wire) and made that connection, so the red jumper cable wasn't connected to the battery ground terminal or anything else...does that matter?

[staninlowerAL]

ck all your grounds

Oh ok, thanks, I might know a place that does that near me.

As for the jumper cables, I had heavy gauge jumper cables and connected one end to the hot on the battery and the other directly to the post on the starter. I didn't hit it hard but I can try that. Also I didn't have the other jumper cable connected to anything, so I just used one cable (I used the black wire) and made that connection, so the red jumper cable wasn't connected to the battery ground terminal or anything else...does that matter?

You might already know it but the starter grounds to the battery through the frame of the tractor so when you only used one jumper cable with no success you might not have been grounded back to the battery. You can try the same approach but with both jumper cables, just make sure that the battery ground is connected to the starter housing. Usually a mounting bolt will work but not if the nut on the bolt is not making good contact with the starter housing. That's what CharlieK was saying when he posted to check all your grounds. JMHO Stan

[jrgkribel22]

Ok thanks I'll try that this evening. I did take the starter off at one point and clean up the flange where it attaches to the tractor to make sure I had bare metal touching bare metal.

[staninlowerAL]

If your unsuccessful getting the starter to turn, I would look for a RR shop to check the starter. Your armature, fields, brushes, bearing, etc might be time for a rebuild.

[jrgkribel22]

Well I'm glad I asked about the jumper cables and ground, you'd think I'd know to ground them when I did that test originally. I redid the test with the one jumper cable on the battery ground and a mounting bolt on the starter, and the other jumper cable on the hot battery terminal then touched the other end to the starter bolt and wouldn't you know, it sparked a whole lot and it cranked!

Now to figure out where the problem is. I'm going to make sure the battery box base, the spot where the ground strap attaches, the base of the dash panel...everywhere I can think of is bare metal and making good contact. Like I said earlier I replaced all the instruments including the key switch and saddle starter button, but I didn't replace any of the wiring. If after cleaning up for grounds I still don't get a start I'll try replacing the cables...any other suggestions?

And thanks again for everyone's help, I really appreciate it!