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My tractor wouldn't start so I brought the battery to John Deere, they tested the battery and said the cells are good and it works fine, they recommended other services, but I declined and came home to ask my neighbor (lawn tractor mechanic). He said the engine was seized due to running on barely any oil, he was right about the oil, and recommended a new engine. I bought a battery load tester, the volts ran good but the load detected a zero reading. I asked John Deere if the mower should start with a zero load, and they didn't provide any info, said they couldn't diagnose over the phone. My neighbor mechanic said the battery ran good until the mower seized, so battery should be good and the volts test good.
I know I need a new battery, but with a zero load detection could this in fact cause the mower to not have any response even-though the volts test good?
 

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I'm not quite sure what you mean by zero load detection. However, some times a bad battery will read close to normal voltage when nothing is attached but then drop to near zero volts as soon as you attach any type of load.
 

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If your motor is seized no battery is going to help get it going.
 

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Tchest, Remove spark plug(s) and see if motor will turnover by hand. If motor is in fact seized, don't worry about a battery! If motor turns by hand, start checking from starter back to ignition switch...looking for voltage or no voltage. Bob
 

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I'm not quite sure what you mean by zero load detection. However, some times a bad battery will read close to normal voltage when nothing is attached but then drop to near zero volts as soon as you attach any type of load.
There's a range on the battery detector, zero being the lowest when detecting the load power. I used the 100 Amp 6/12V Battery Load Tester by Cen-Tech.
 

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If your motor is seized no battery is going to help get it going.
I know, I just didn't know if the seized engine diagnosis was wrong. I have to get my tractor back to put a new battery in, but in the meantime was trying to get more knowledgeable if the tractors engine was good, could it still not start or have any response with a battery that has good volts (fully charged) but no load power.
 

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Tchest, Remove spark plug(s) and see if motor will turnover by hand. If motor is in fact seized, don't worry about a battery! If motor turns by hand, start checking from starter back to ignition switch...looking for voltage or no voltage. Bob
Thanks Bob! My mechanic currently has the tractor, but he's the one who diagnosed it as being seized. He didn't tell me how he determined this, he's a little rough around the edges to talk to. I appreciate your help, and may check into this when I get the machine back.
 

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I'm not quite sure what you mean by zero load detection. However, some times a bad battery will read close to normal voltage when nothing is attached but then drop to near zero volts as soon as you attach any type of load.
I'm mystified by that as well. Best guess:

Any power source can be modeled using a Thevenin equivalent circuit. This consists of a theoretical battery that can supply infinite current @ 12V in series with a resistor that represents the battery's internal resistance. In order to be able to supply 100A, that resistor value needs to be very low - a fraction of an ohm. Using Ohm's law, you can put a load of known resistance across the battery, measure the voltage across it, and calculate the value of the internal resistance. If it is too high then the battery will be unable to source 100A at anything close to 12V.

Al
 

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Thanks Bob! My mechanic currently has the tractor, but he's the one who diagnosed it as being seized. He didn't tell me how he determined this, he's a little rough around the edges to talk to. I appreciate your help, and may check into this when I get the machine back.
As a previous poster suggested, remove the spark plugs and see if it spins with the starter. You can also remove the flywheel shroud and rotate the engine by hand (with spark plugs removed).

If it spins by either method above it is not seized. BUT - you may still have other internal issues from running with low oil.
 

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There's a range on the battery detector, zero being the lowest when detecting the load power. I used the 100 Amp 6/12V Battery Load Tester by Cen-Tech.
The electronic testers are nice for some things but I sometimes like to do a quick test with a simple analog load tester. You can usually pick these up for around $20. If you can't stay within the green range for a few seconds the battery is toast.
 

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I know, I just didn't know if the seized engine diagnosis was wrong. I have to get my tractor back to put a new battery in, but in the meantime was trying to get more knowledgeable if the tractors engine was good, could it still not start or have any response with a battery that has good volts (fully charged) but no load power.
You never said which tractor / engine you have. Some engines, especially the single cylinder models, have an internal compression release mechanism on the cam. In most cases if it is malfunctioning the starter will not have enough power to turn the engine over. The starter will usually sit there and whine at you giving the indication of a bad starter or bad battery.

Turning the engine over by hand with the spark plug(s) removed is the best way to see if it is seized.
 

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I'm mystified by that as well. Best guess:

Any power source can be modeled using a Thevenin equivalent circuit. This consists of a theoretical battery that can supply infinite current @ 12V in series with a resistor that represents the battery's internal resistance. In order to be able to supply 100A, that resistor value needs to be very low - a fraction of an ohm. Using Ohm's law, you can put a load of known resistance across the battery, measure the voltage across it, and calculate the value of the internal resistance. If it is too high then the battery will be unable to source 100A at anything close to 12V.

Al
I don't know, I do appreciate your help though. All I know is, the load tester is at 0. This video shows what I'm talking about on youtube, their battery load is good but mine is at 0. Check this video out, start it a 2:26-2:59. Just need to see this 30 sec of it. Hope this helps.
 

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I don't know, I do appreciate your help though. All I know is, the load tester is at 0. This video shows what I'm talking about on youtube, their battery load is good but mine is at 0. Check this video out, start it a 2:26-2:59. Just need to see this 30 sec of it. Hope this helps.
Your link didn't come through for the YouTube video. I would like to see what you are talking about.
 

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The electronic testers are nice for some things but I sometimes like to do a quick test with a simple analog load tester. You can usually pick these up for around $20. If you can't stay within the green range for a few seconds the battery is toast.
This is the exact tester I used. The volts were good, but the load test was at zero. I just don't know, regardless of any other issue. would there be any response from the tractor if the volts were good but the load was at zero?
 

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This is the exact tester I used. The volts were good, but the load test was at zero. I just don't know, regardless of any other issue. would there be any response from the tractor if the volts were good but the load was at zero?
Oh! Ok... I thought you were using one of the electronic testers. I apologize then as I still don't quite understand how you were seeing "zero load test". When you attach this tester the meter should read the battery voltage. Then when you activate the load switch the meter should drop some (or go to zero if the battery is totally bad). In the snap shot below from the video you referenced, the load button is activated and the meter is somewhere in the green zone. If you do not activate the load button it isn't testing anything. Did it act differently for you?
 

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If voltage is good on the tester at NO LOAD ........then it goes to ZERO 0 volts under the tester load .........then you have a direct short somewhere in the system......either the tester or the battery or bad clamp connections

IF the battery is shorted internally then it would not turn over the starter on the mower

I would be suprized that john deere or any competent mechanic would declare a battery good without some form of load testing

I would also be suprised that any competent mechanic would declare a engine siezed without doing more than turning the starter key

places like walmart can also test your battery

good mechanics can also diagnose your engine

i have jump started mowers from my car before

i have pulled spark plugs and found engines hydrolocked with oil etc and wouldnt turn over but not siezed

from the information you have proided its impossible to diagnose your problem and it appears from your skill and experience levels you need to visit a competent mechanic

just my opinion
 

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Oh! Ok... I thought you were using one of the electronic testers. I apologize then as I still don't quite understand how you were seeing "zero load test". When you attach this tester the meter should read the battery voltage. Then when you activate the load switch the meter should drop some (or go to zero if the battery is totally bad). In the snap shot below from the video you referenced, the load button is activated and the meter is somewhere in the green zone. If you do not activate the load button it isn't testing anything. Did it act differently for you?
You are awesome. To look into this for me, I really appreciate it. I don't know much about this, thanks for working with me. So the battery voltage is good, stays at 12, but when I activate the load the meter drops to zero and doesn't move. I just didn't know if there could still be a response from the tractor (like the lights could still go on, or there could be noise like it's trying to kick over, ect) and have a battery with good volts but have a zero load result. Hope that makes sense.
 

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You are awesome. To look into this for me, I really appreciate it. I don't know much about this, thanks for working with me. So the battery voltage is good, stays at 12, but when I activate the load the meter drops to zero and doesn't move. I just didn't know if there could still be a response from the tractor (like the lights could still go on, or there could be noise like it's trying to kick over, ect) and have a battery with good volts but have a zero load result. Hope that makes sense.
Ok... it makes sense now. Based on your description it seems very likely that your battery is totally defective. It will never crank or start a lawn tractor motor in that condition. The tester is not saying that you have zero AMPS, the meter is saying the VOLTAGE of the battery is dropping to ZERO VOLTS under load. Keep in mind, the meter on that tester is reading VOLTS, not AMPS. The part that still causes some confusion is you saying the JD mechanic tested your battery and said it was fine. Batteries are fairly easy to test so I'm not sure what method he used to declare it was ok.

Do you have a battery charger available? The only thing remaining is to try to charge the battery using a slow trickle charge and then repeat your test with the battery tester.
 

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If voltage is good on the tester at NO LOAD ........then it goes to ZERO 0 volts under the tester load .........then you have a direct short somewhere in the system......either the tester or the battery or bad clamp connections

IF the battery is shorted internally then it would not turn over the starter on the mower

I would be suprized that john deere or any competent mechanic would declare a battery good without some form of load testing

I would also be suprised that any competent mechanic would declare a engine siezed without doing more than turning the starter key

places like walmart can also test your battery

good mechanics can also diagnose your engine

i have jump started mowers from my car before

i have pulled spark plugs and found engines hydrolocked with oil etc and wouldnt turn over but not siezed

from the information you have proided its impossible to diagnose your problem and it appears from your skill and experience levels you need to visit a competent mechanic

just my opinion
Thank you for your time. I have no skills or experience, just a home owner that now has a tractor that doesn't work. I don't want to doubt my mechanics opinion, but I just didn't know if the tractor would totally not work if there was NO LOAD and it goes to ZERO (Although the voltage is good), or should I still be able to get some response like lights flickering or something. I appreciate your time.
 
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