Deere LA 110 won't start

JohndeereLA110

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The mower will not turn at all. The lights come on, so I know the battery is good (I tried jumping the battery just in case but that didn't help). I replaced the selodoid, ignition switch, seat safety switch, and, blade safety switch. I have not replaced the clutch safety switch. The fuse looks good. The engine will start if I place a metal screwdriver across the selodoid terminals.

What else could be the problem?
 

Mikel1

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Do you have a multimeter? If you do then check the dc voltage on the the terminal wire(small) of solenoid, there are two terminals from the diagram I see, one is a ground and the other energizes when the starter should spin. Just unhook that wire and insert positive probe, negative probe to good ground. Leave the other wires in place on the solenoid and try to start it like you normally would. Now is there any voltage on it?
 

Rivets

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Here is a more detailed procedure of what Mikel1 would like you to do. Post back your results and one of us will help you out.





Electrical* problems can be very easy or very difficult, depending on four things.
1. * How well you understand basic electricity.
2. *What tools you have and know how to use.
3. *How well you follow directions.
4. *You don't overlook or assume anything and verify everything.

Remember we cannot see what you are doing. *You are our eyes, ears and fingers in solving this problem. *You must be as accurate as you can when you report back. *The two basic tools we will ask you to use are a test light and a multi-meter. *If you have an assistant when going through these tests it would be very helpful. *These steps work the best when done in order, so please don't jump around. *Now let's solve this problem.

First, check the fuse(s), check battery connections for corrosion (clean if necessary) and *voltage - above 12.5 volts should be good.*

Second, check for power from the battery to one of the large terminals on the solenoid. *One of the wires is connected directly to the battery and has power all the time so one of the large terminals should light a test light or show 12 volts on a meter at all times.*

Third, *check for power at the small terminal of the solenoid while depressing the clutch/brake pedal and holding the key in the start position (you may need an assistant to sit in the seat to override the safety switch). If your solenoid is a four wire solenoid, check both small wire terminals as one is ground and the other is power from the ignition switch. *If your solenoid is a three wire solenoid, make sure the solenoid body is not corroded where it bolts to the chassis of the mower as this is your ground path back to the battery. *If in doubt, remove the solenoid and clean the mounting area down to bare metal. *If there is no power to the small terminal then your problem is most likely a safety switch, ignition switch or in the wiring.*

Fourth, check for power on the other large terminal of the solenoid while holding the key in the start position (you may need an assistant to sit in the seat to override the safety switch).*

Fifth, check for power at the starter while holding the key in the start position (assistant again).*

Sixth, check your ground circuit back to the battery.

After you have gone through each of the above steps, let us know what happened when you did each step. *At that point we will have great info to tell you how to proceed. *Remember you are our eyes, ears, and fingers, so please be as accurate as possible.

Be as specific as possible with voltage readings as this will help diagnose your problem quicker. *If you do not know how to perform the above checks, just ask and I will try to guide you through it. *Youtube also has some videos and as you know a picture is worth a thousand words.
 

JohndeereLA110

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Thanks for the help

I did all of the above except number 6, because I didn't understand how to do that. The solenoid bolt that connects to the battery did not register a voltage. However, the solenoid bolt that connects to the starter registered approximately 12; the connection at the starter registered 12; the two small plug in connections on the solenoid registered 12.

Just to be sure, I replaced the fuse. Corrosion is not an issue.

Could it be the clutch safety switch?
 

Mikel1

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On the solenoid stud coming from the battery cable on the + battery post doesn't register a voltage? If you had 12+V at starter then starter would spin. You can still short solenoid stud terminals and still start, correct?
 

Rivets

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Are you saying that in step 2 you had no voltage, but in step 4 & 5 you do have voltage? In step 6 I want you the check that you have a good tight clean connection on the negative battery cable, both at the battery and where it bolts to the chassis.
 

JohndeereLA110

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On the solenoid stud coming from the battery cable on the + battery post doesn't register a voltage? If you had 12+V at starter then starter would spin. You can still short solenoid stud terminals and still start, correct?

I found the problem. The clutch safety switch was bad. I replaced it and it starts perfectly.

Thanks for helping me narrow it down.
 

JohndeereLA110

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Are you saying that in step 2 you had no voltage, but in step 4 & 5 you do have voltage? In step 6 I want you the check that you have a good tight clean connection on the negative battery cable, both at the battery and where it bolts to the chassis.

Yes...the solenoid post that connects to the battery did not have a voltage, but everything else did. I don't understand how I could put the screwdriver across both solenoid posts and see sparks and start the engine, but the voltmeter did not register a reading when I tested it. I put one lead on the battery positive (red) terminal and one to the solenoid posts that connects to it and did not get a reading.

Regardless, the problem was the clutch/brake safety switch. I replaced it and it starts perfectly now.

Thanks for the help.
 

JohndeereLA110

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My success was short lived. I tried to start the mower again and had the same problem. I assume this means there is an electrical short somewhere. Any idea how to find which wire from the millions of wires in there?
 
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