8N Electrical Issue

[Xfaxman]

I had a chance to look at the tractor today. Double-checking all my connections as I put the battery back in....I noticed there is zero resistance between starter stud and ground/starter body. I disconnected from solenoid just to make sure that wasn't grounding out. I vaguely remember that maybe being the case with my old starter too. Is that normal, or maybe an issue?-----------

I am guessing that you know the meter has to be on the lowest ohms scale to measure this.

If you didn't know it, check this: Multimeter Tutorial

 

[Scrambler82]

When you measured the RESISTANCE, did you try to start the engine ?

 

[Scrambler82]

Thinking... wood burning again, do you mean continuity is what you were checking for ?

 

[aschwerin]

At least its not a cheap consumer grade VOM. I was just doing the beep setting, checked again and actual measurement is .9 ohms

Xfaxman: it is an autoranging multimeter

Scrambler82: Aren't resistance and continuity two sides of the same coin? I did not check it while trying to start. I'm not sure what that is to tell me?

I pulled all the plugs out resulting in no improvement. That's a lot of arrows pointing to the starter(s) as the culprits. Maybe I'm being stubborn, but I'm just finding it hard to believe that the rebuilt original and a fairly new aftermarket starter both are broken in the same way. If nobody has a better suggestion I'll pull it out.

 

[Xfaxman]

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If the bats are good, and the connection are good, and the tractor runs once started, look at the starter and drive.

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Soundguy, that sounds like good troubleshooting. By drive you mean starter gear/flywheel/crankshaft?

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I think I came on here because I really wanted to validate what Soundguy has validated. With a good connection, putting a good battery on a starter should always spin it. Either there is too much force in the tractor for the starter to overcome, or there is a problem with the starter.

It may not spin it if the Bendix is stuck out, engaged with the ring gear.

Put it in neutral, with a socket and breaker bar on the crankshaft nut, turn it some both ways, (remove the wrench ) then try to jump it.

 

[Scrambler82]

At least its not a cheap consumer grade VOM. I was just doing the beep setting, checked again and actual measurement is .9 ohms

Xfaxman: it is an autoranging multimeter

Scrambler82: Aren't resistance and continuity two sides of the same coin? I did not check it while trying to start. I'm not sure what that is to tell me?

I pulled all the plugs out resulting in no improvement. That's a lot of arrows pointing to the starter(s) as the culprits. Maybe I'm being stubborn, but I'm just finding it hard to believe that the rebuilt original and a fairly new aftermarket starter both are broken in the same way. If nobody has a better suggestion I'll pull it out.

No continuity is just checking to see if the is a connection between two points, checking for a shorted condition.
Checking for Resistance is just that checking for how much resistance there is between two points or directly on a resistor, usuall a voltage needs to be applied in order to determine the resistance factor and usually resistance creates voltage drop. By determining the total resistance in each component in a circuit you can tell the total voltage drop from the beginning of the circuit to the end.

To me I would start by determining if you want to retain a 12 volt system, a good idea.
Then attempt to locate a 12 volt version of the starter. This IMHO will be the hardest thing to do; if you can't find a 12 unit try to find some one that can rebuild it for 12 volt use.

The biggest problem in using a 6 volt starter in a 12 volt system is that the 6 volt unit pulls more current than a 12 volt unit. Yes it may spin faster for a while and yes it may last long enough to get a few years out of the system but the outcome is simple, the start or the battery WILL destroy one another.


Luck on your search.

 

[Soundguy]

Spoken like someone who has no experience with old tractors!!

Lots. Thousands upon thousands of old tractors that came out 6v are running on 12v with the same starters, I have many 12v converted units running on is starters, the couple year failure rate you quote is not typical.

 

[aschwerin]

When cranking the ignition key, the resistance of the starter goes to infinite. The voltage reads around 1.6 volts. So its like the starter is "sucking" the amperage, but can't get enough to turn the engine.

I don't post much, but I read through these forums a lot when fixing things (the tractor was a pasture ornament when I got it). I don't remember reading anything about converting a starter to 12V. I would think that would turn most people off through the last few decades in doing the conversion.

So that said, it really is like the batteries are going bad, but its a matter of months rather than years. A poor alternator didn't help (replaced a few weeks ago). But I've brought the batteries into battery centers and they test with good voltage and good cranking amps. Electrolyte levels are fine. From my experience with this tractor, if I bought some $150 900 CCA deep cycle marine battery for the tractor, it would start fine for like 6 months. I'm still in the red on this machine and can't be sinking $300 a year into batteries.

 

[Xfaxman]

When cranking the ignition key, the resistance of the starter goes to infinite. The voltage reads around 1.6 volts. So its like the starter is "sucking" the amperage, but can't get enough to turn the engine.

------------I'm still in the red on this machine and can't be sinking $300 a year into batteries.

You can't measure resistance with voltage on the circuit.

What is the voltage on the battery post when cranking? If it isn't 1.6v, you have a cable or solenoid contacts problem.

If it is 1.6v you have a bad battery.

If you had watched the video that I posted in #10, you would have fixed it by now. https://www.youtube.com/watch?v=XhRPLgH6uZg

 

[aschwerin]

I hate videos. But I watched it, and it was very educational.

Batteries measured 3V and starter 1.6V, so that's a sorry battery (difference is probably from jumper cables). I read a lot at Battery University and batteries can be bad even if voltage and CCA show good readings. Sulfation and such. I'm thinking I have a lot of not perfect batteries around here. However, I had a friend's pickup just before I started this thread and tried jumping the tractor with the a brand new battery in it, still wouldn't crank.

So I unhooked the jumper cables from the tractor and jumped straight to the starter from that battery. 10V on battery and 1.6V on starter post. So the jumper cables were not a great connection. I am charging that battery overnight (currently at 13.1V) and will install it in tractor next chance I get.