L3010 HST won't start. Battery good, starter good

[Tenalach Farms]

I'm pretty sure this has come up before my search efforts have not found anything helpful. Apologies if anyone feels like this has been beat to death before I have a shop manual, but the information in it does not help Me to find some of the likely culprits in the electrical system - various safety switches.
My meter says I'm getting 12 volts at the starter with the key off, and when I turn it to start that reading drops to more like 4-5 volts. No sound with the key in start position. Indicator lights come on. Sometimes there's a low almost hissing sound as the key moves back to the On position. I've checked battery connections - replaced the grounding cable not that long ago because of intermittent problems there, the positive side is good and my meter reads 12 volts across the battery. I replaced the old starter hoping it would be that simple a fix, but of course not. Jumping the old starter, it runs. For now, assuming the new starter is good.
I need some KISS advice/instructions on how to track down this problem. Really need the tractor running, and my local shop has given me the runaround and doesn't think they can extract it from where it is, less than 50' off my driveway
Thanks in advance.

 

[JimDeL]

Check the connection of the negative cable to the chassis ground. Make sure it's clean and is connecting to BARE METAL.

 

[Tenalach Farms]

Check the connection of the negative cable to the chassis ground. Make sure it's clean and is connecting to BARE METAL.

All that was part of the recently replaced ground cable described in my post.

 

[johnjk]

Look to see how many safety switches you have. Common areas are the clutch pedal and seat. They may ohm good but you could be dropping voltage across them and that solenoid on the starter is looking for that 12V signal. For testing you can jumper the safety switches out and test. I had drops on my safety switches and ended up wiring in a relay that sends 12V to that solenoid even if the voltage off the safety switches is below 12V. The other thing to check is that you don’t have a safety switch that has worked loose and backed off so it is not getting depressed and making contact.

 

[Moose7060]

Since you have checked all the connections including the ground, I would load test the battery. 12v doesn't always equate to good. Just a suggestion. Good luck.

 

[PoTreeBoy]

I'm pretty sure this has come up before my search efforts have not found anything helpful. Apologies if anyone feels like this has been beat to death before I have a shop manual, but the information in it does not help Me to find some of the likely culprits in the electrical system - various safety switches.
My meter says I'm getting 12 volts at the starter with the key off, and when I turn it to start that reading drops to more like 4-5 volts. No sound with the key in start position. Indicator lights come on. Sometimes there's a low almost hissing sound as the key moves back to the On position. I've checked battery connections - replaced the grounding cable not that long ago because of intermittent problems there, the positive side is good and my meter reads 12 volts across the battery. I replaced the old starter hoping it would be that simple a fix, but of course not. Jumping the old starter, it runs. For now, assuming the new starter is good.
I need some KISS advice/instructions on how to track down this problem. Really need the tractor running, and my local shop has given me the runaround and doesn't think they can extract it from where it is, less than 50' off my driveway
Thanks in advance.

Some time ago, somebody posted a detailed procedure. I'll try to get you started. If your voltage across the starter is only 5 volts, you either have a battery or connection problem.
1. Put you VOM probes on the battery posts, not the connectors. When you hit the starter, what's the reading? If below 9 or so, your battery is the problem. Assuming it's ok, go to 2.
2. We want to find where the voltage drop is, a bad connection. Keep the + probe on the battery + post. Then take readings (must be while trying to start, so you have high current) at + battery clamp, starter end of + cable, starter + post. Any voltage reading over 0.5v shows a bad connection. Then work from the - battery post to the - battery clamp, ground connector and engine ground. You'll find either a bad cable or bad connection.
If you get 11 volts or so at the starter and it won't crank, then you have a bad starter or starter solenoid.

 

[GreensvilleJay]

Sounds like you need to replace the +ve battery cable.
1) good battery
2) good ground cable(new)
3) +12 on starter stud , when key off.
4) +4-5 on starter stud when key turned to 'start'
5) new starter

When you power the starter relay, +12 stud on starter drops to 4 or 5 volts. That and the hissing, indicates a lot of current is trying to pass through but meeting 'some' resistance. THAT resistance drop the voltage down and starter won't spin.

Curious as to why you didn't replace BOTH battery cables.

 

[DustyRusty]

Without a load test on the battery you have no idea of how good it actually is. I have seen batteries show 12 volts, but they didn't have any cold cranking ability. Only good for lighting a tail lamp bulb. I know you said that you replaced the negative cable, but take it off the frame and check it again. A lot of corrosion can happen in a short time. Do the same with the positive cable. Also using a battery brush clean the terminals on the battery and the inside of the terminals on the battery cables. If you are using the clamp on replacement ends on the battery cables, ditch them and purchase some quality battery cables. Your tractor deserves the best products to continue to be reliable.