Electrical Problem

[moljacama]

I have a Yanmar 3000 which I got in February. It has been cranking perfectly - not slow, etc. I did some bush hogging for about 2 hours yesterday and did not have the slightest problem. Once finished, I parked the tractor. I shut off the throttle and then decided that I wanted to park it somewhere else.

I then turned the key and the starter began turning the engine. I quickly realized that the throttle was still off. I turned the key back to off, adjusted the throttle so that it would crank, and then turned the ignition again. This time there was nothing. The starter did not move or make a sound.

I have tried jumping the contacts on the starter solenoid. There was a very faint spark but the starter did not move. I did some searching on this forum about what the culprit might be but I did not find anything definitive. I also tried jump starting the tractor but the jumper cables started smoking and the fan on the tractor turned a few times even though the key was in the off position. I am positive that I had the cables properly connected.

If anyone has experienced this before or has an idea about what to check I'd love to hear it.

 

[winston1]

Are you saying the cables started smoking when you hooked them up, not even trying to crank, with the key in off position??

 

[mikereid]

on old cars I used to tap a starter with a hammer if they get stuck (tap lightly on the side near the back) LIGHTLY!!!

 

[moljacama]

Winston1,

After hooking up the cables I turned the key. I saw the fan turn somewhat slowly for about 2 seconds. I returned the key to the off position. A few seconds later the fan turned at a slow speed for about 2 seconds.

I tried turning the key to "crank" again and noticed that the fan would turn a few times and then stop. I turned the key back to off once more and got off the tractor. The fan once again turned a few more times on its own. At this point, I noticed a slight trail of smoke coming from the jumper cables attached to the tractor. The insulation on the cables was beginning to melt! I quickly disconnected the cables.

I visually examined all of the wiring this afternoon but couldn't find anything obvious. At this point, I am suspicious of the ignition switch since the fan and motor would turn while the key was in the off position. Perhaps there was a short or something with the switch and it drained the battery. However, I would be the first to concede that I am not much of an electrician and would gladly follow any advice.

 

[winston1]

OK, as I understand it, nothing is happening now unless you hook up jumper cables? Sounds like something is grounded out. Check your battery voltage with a voltmeter. Should have 12+ volts. If your starter is turning without ignition on I expect your battery is dead at this point. To isolate the starter you can remove the 2 small wires from the solenoid and then try jumping across the solenoid. That would take the switch and all other electrical out of the picture. Another option is pull the starter and have it tested.

 

[normde2001]

I would start by taking a good look at the switch for a short.

 

[clemsonfor]

bATTERY could just be dead but dosent explain the smoke just the not starting problem at first. I have had car batteries fine drive somewhere then 10 mins later not even a click. Make sure the postitive cable is not touching the hood or radiator shroud, its very tight in the hood area. Starter may be drawing to many amps and burning the wires up, but it should be the starter lead first as im sure its probly smaller wire than your cables.

One more thing, are these those super cheap pencil thin emerengcy jumper cables. My wife had a set that her dad put in her car, they were good for a few jumps but really undersized. They started smoking while i use to jump my 12 hp riding mover, it was just that there was too much current pulled through the size wire, heavy duty cables no problem.
This may also be why it turns a little but no start, the wire cant allow enough power through them to start.

 

[moljacama]

I figured it out. It was a bit of a brain twister for awhile though. Apparently the spring on the starter solenoid was out of place enough so that the solenoid could not be disengaged. This resulted in the solenoid being constantly energized.

I did waste a bit of money on a new ignition switch when it turned out that there was nothing wrong with the old one.

I also purchased a new battery since the old one was completely zapped by the solenoid being constantly engaged for 5 days.

A big thank you to everyone that replied. Your comments really helped me out. I am going to get some heavier duty jumper cables also. I am just thrilled to have my tractor running again.