SST61V-26DFI Won’t start

Knots

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Turf Tiger will not start. Engine will run but won’t start unless you momentarily jump a lead from the positive battery terminal to the spade lug on the starter solenoid. This works 100% of the time and will run fine until shut off. Then it won’t start. Any ideas of where to start looking? Have tried bypassing all safety switches, etc..
Thanks,
Knots
 

Mad Mackie

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Behind the panel close to the key switch is the cranking relay. When all the safety circuits are operating and positioned correctly, the electronic safety module will ground the cranking relay and and allow power to the starter solenoid for cranking the engine over.
This relay is a fairly often the cause of a no cranking condition.
On page 76 of the parts manual this relay is figure # 9. The electronic module is figure # 31.
On page 84 is the electrical schematic for your machine, the cranking relay is the one in the top L/H corner.
 

Knots

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Mad Mackle
Found that the two wires coming off the ammeter were stuck together about an inch from the spade connectors. Looked like they had been hot. Pulled them apart and the conductors were showing on both wires. Insulation melted together at that point.
Taped up wires and rerouted them. Ammeter now working and no start issues.
Hope that was the problem.
Just FYI

KNOTS
 

Luffydog

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How about the yellow wire going to the key switch is it burnt or been hot? Those wires to the amp meter being burnt or to the key switch might be an early sign of a bad ground or the charging starting to get weak and the pto clutch might be starting to fail as well. Checking the and the charging and keep eye out if it keeps doing those things might be the early signs that I have said.
 

Knots

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Looks like you dropped a word after “checking the”. Please advise. Thank you.

Knots
 

Knots

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Luffydog,
Yellow wire to ignition switch seems fine.
Yellow with red stripe to left hand lug (as viewed from the rear) on ammeter seems to be the culprit.
I noticed a couple of years ago
that the blue nylon insulator on that wire appears to have been hot at some point and that may we’ll have been when wires melted together and shorted causing the no-start issue. Red ,and red with yellow stripe to other ammeter lug appear normal except where they got hot and fused together.
Scag dealer replaced all relays, switches, and module under dash under warranty. Some were replaced twice. Any additional thoughts would be greatly appreciated.
BTW, the shorted wires may have been the problem from day one.

Thank you,
Knots
 

Luffydog

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Yes check the pto another the clutch might be pulling more than it is supposed to be pulling. Check the ohm reading cold. On the bottom of the clutch might have a tag with some numbers of some of them depends on the clutch might test somewhere from 2.4-2.8 too low below 2.4 is bad and over 2.8 is also bad. Have you been replacing the pto switch a lot? With those wire to the meter being burnt hot and stuck together says it was pulling a heavy load to get them hot. Lights,bad battery,fuel pump,no charging, clutch with the most being the clutch or all at the same time pulling to much and the charging just can't simply keep because something is pulling more of a load than it should causing a heat failure to the weakest spot of the system.
 
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