The advice I've seen in this forum is very impressive. So I'm sharing my story - and it is humbling. The moral of this story is to not skip the simple things. CHECK THEM FIRST.
I was about to send this (See "The original story..." below) but after I typed this I figured I'd do a bit more troubleshooting. I tore apart more of the tractor so I could get to the battery ground on the engine block. It was corroded. Not easily seen due to the typical grass/grease/muck in there but once I took it apart the joint, the bolt, nut and ends of the two grounds that go there were corroded. Cleaned it up with a file, wire brushes and a dremel and WHA LA!!! Tractor cranks like normal! The ground was the problem. I'm sharing this because $75 in parts and 20-25 hours of labor/research/fretting later, it was a ground issue. And aruguably the first oneI should have checked. If I had taken things apart to get to this first, it would have save me a lot of time and money. But I didn't because the problem seemed to be a starter issue since the starter wouldn't turn over when the solenoid was jumped. Then I figured it must be the solenoid since the starter didn't fix it. Then I get more into it with the meter and saw the strange voltages (after $75 in parts). Then I said - come on - it won't crank at all now! And back to basics - tear more things apart and start from the beginning.
Turns out - the ground was so bad that the battery couldn't deliver the proper voltage and current to the starter. Couldn't even get the solenoid to fully engage! I had to keep the battery fully charged recently - I guess to overcome the bad ground...
I'm not an electrical engineer and can't explain why the funny readings were received below - maybe someone else can for my learning - but it had me off starting to look at safety switches, wiring, etc... I was even wondering why my batter was dying so often. It was likely the small voltage draw when the key was left in the on position.
If you can explain the strange voltage readings below - I would be appreciative. To all others - hopefully you aren't as lazy about checking grounds as me.
_________
The original story/request for help (Now no longer needed):
I own a Craftsman Zero turn ZTS7500 (107.26786) mower and owners manual but no electrical diagram. Tractor has had an issue where it would not always crank when the key was turned. Seemed like the starter. I replaced the starter and no improvement. Next the solenoid was replaced. Mower would crank occasionally, but not every time the key was turned. And now since I started doing more electrical troubleshooting, it won't crank at all when the key is in the 'START' position. With the new 4 pole solenoid I took some more readings.
Four terminals: #1 solenoid left side from battery + terminal; #2 solenoid right side to starter; #3 small left side (Blue wire) (under terminal 1); #4 small right side (yellow wire) (under terminal 4).
Battery was bought in July and was load checked and shown to be good earlier this week. I left the key "ON" all night and it drained from 12.7V to 12.3V when I took the readings below. (See voltages below when key is in 'ON' position). It's on a Battery Tender right now. So, here is what I've been able to find:
With the key in the OFF position I have the following voltages:
#1: 12.3 Volts; #2, #3, #4: 0 volts
With the Key in the ON position I have the following voltages:
#1: 12.3 volts; #2: 0.6 Volts; #3: 0.6 Volts; #4: 0.6 Volts
With the Key in the START position I have the following voltages:
#1: 12.3 volts; #2: 2.5 Volts; #3: 12.1 Volts; #4: 6.4 Volts
With the Key in the START position I have the following voltages:
#1: 12.3 volts; #2: 2.5 Volts; #3: 12.1 Volts; #4: 6.4 Volts
If any of the safeties are not engaged, or the PTO switch is on, the voltages are all 0 on #2, #3 and #4 terminals.
Now I get nothing when I turn the key. I've also tried shorting across the solenoid and get a few sparks but no crank.
I'm having trouble figuring out where to look from here. And I don't have electrical diagrams - if someone can provide them it would be a huge help. I suspect something with the key switch, or ground, but don't know how to troubleshoot the key switch.
Thank you!
I was about to send this (See "The original story..." below) but after I typed this I figured I'd do a bit more troubleshooting. I tore apart more of the tractor so I could get to the battery ground on the engine block. It was corroded. Not easily seen due to the typical grass/grease/muck in there but once I took it apart the joint, the bolt, nut and ends of the two grounds that go there were corroded. Cleaned it up with a file, wire brushes and a dremel and WHA LA!!! Tractor cranks like normal! The ground was the problem. I'm sharing this because $75 in parts and 20-25 hours of labor/research/fretting later, it was a ground issue. And aruguably the first oneI should have checked. If I had taken things apart to get to this first, it would have save me a lot of time and money. But I didn't because the problem seemed to be a starter issue since the starter wouldn't turn over when the solenoid was jumped. Then I figured it must be the solenoid since the starter didn't fix it. Then I get more into it with the meter and saw the strange voltages (after $75 in parts). Then I said - come on - it won't crank at all now! And back to basics - tear more things apart and start from the beginning.
Turns out - the ground was so bad that the battery couldn't deliver the proper voltage and current to the starter. Couldn't even get the solenoid to fully engage! I had to keep the battery fully charged recently - I guess to overcome the bad ground...
I'm not an electrical engineer and can't explain why the funny readings were received below - maybe someone else can for my learning - but it had me off starting to look at safety switches, wiring, etc... I was even wondering why my batter was dying so often. It was likely the small voltage draw when the key was left in the on position.
If you can explain the strange voltage readings below - I would be appreciative. To all others - hopefully you aren't as lazy about checking grounds as me.
_________
The original story/request for help (Now no longer needed):
I own a Craftsman Zero turn ZTS7500 (107.26786) mower and owners manual but no electrical diagram. Tractor has had an issue where it would not always crank when the key was turned. Seemed like the starter. I replaced the starter and no improvement. Next the solenoid was replaced. Mower would crank occasionally, but not every time the key was turned. And now since I started doing more electrical troubleshooting, it won't crank at all when the key is in the 'START' position. With the new 4 pole solenoid I took some more readings.
Four terminals: #1 solenoid left side from battery + terminal; #2 solenoid right side to starter; #3 small left side (Blue wire) (under terminal 1); #4 small right side (yellow wire) (under terminal 4).
Battery was bought in July and was load checked and shown to be good earlier this week. I left the key "ON" all night and it drained from 12.7V to 12.3V when I took the readings below. (See voltages below when key is in 'ON' position). It's on a Battery Tender right now. So, here is what I've been able to find:
With the key in the OFF position I have the following voltages:
#1: 12.3 Volts; #2, #3, #4: 0 volts
With the Key in the ON position I have the following voltages:
#1: 12.3 volts; #2: 0.6 Volts; #3: 0.6 Volts; #4: 0.6 Volts
With the Key in the START position I have the following voltages:
#1: 12.3 volts; #2: 2.5 Volts; #3: 12.1 Volts; #4: 6.4 Volts
With the Key in the START position I have the following voltages:
#1: 12.3 volts; #2: 2.5 Volts; #3: 12.1 Volts; #4: 6.4 Volts
If any of the safeties are not engaged, or the PTO switch is on, the voltages are all 0 on #2, #3 and #4 terminals.
Now I get nothing when I turn the key. I've also tried shorting across the solenoid and get a few sparks but no crank.
I'm having trouble figuring out where to look from here. And I don't have electrical diagrams - if someone can provide them it would be a huge help. I suspect something with the key switch, or ground, but don't know how to troubleshoot the key switch.
Thank you!