Scag STT52A-CH25 has been starting for months after several attempts turning key to start. Now I can't get it to start without jumping the solenoid. I've replaced the ignition switch, ign. relay, and solenoid. I get full (12.8V) battery voltage, with key on start position, on green/white wire from relay up to the engine harness. With light blue wire going to the solenoid connected, I read 0 volts with key to start. Blue wire test no resistance from harness. A red wire going into the engine is connected to same pin with blue at connector. I've cleaned engine ground and replaced terminal ends on wires. I've ground tested white wire at the same connector (on engine harness) and all safety switches seem good. I tested PTO switch with ohm meter - good, tested seat and park brake - good, and could not get to switches on control arms. (They tested good through white wire ground test). I've not found any rodent damage to wiring nor corroded connections. I feel like this is a wiring problem and short of replacing the interface module, I don't know what else to look for. ANY suggestions are welcome ...
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Export threadI would test the ignition switch without it connected to anything, use an ohm meter or use jumper with 12volts to the correct terminal on the switch , turn to on position and verify power, then start position and watch your test light , I've seen bad ignition switches straight out of the box. If everything passes then start looking at harness connections / wires.
I have 12.8V from the switch through the ignition relay to the engine pigtail. That's where it ends.I would test the ignition switch without it connected to anything, use an ohm meter or use jumper with 12volts to the correct terminal on the switch , turn to on position and verify power, then start position and watch your test light , I've seen bad ignition switches straight out of the box. If everything passes then start looking at harness connections / wires.
I tried that and was surprised that I got no results. I will try again today with better wire connection.Unplug the pigtail and use a jumper straight to the starter solenoid small terminal , maybe your pigtail connection is corroded
I tried jumper wire from harness to solenoid again and I lose power when I connect to the tab. ?? It's like it grounds out when I touch 12V to it. I changed the solenoid back to the old one and got the same results.I tried that and was surprised that I got no results. I will try again today with better wire connection.
With so many items replaced and never tested the old ones, I would make sure every wire at the key switch is connected proper. Use reading glasses if needed. I do..... If one wire is not in the correct spot.......
Pull the spark plug/s. See if it cranks/spins over the engine.
Were these new parts all OEM?
Pull the spark plug/s. See if it cranks/spins over the engine.
Were these new parts all OEM?
The first part I replaced was the start relay. It was a used part I had and assumed was good. Key switch was OEM. Solenoid was not.With so many items replaced and never tested the old ones, I would make sure every wire at the key switch is connected proper. Use reading glasses if needed. I do..... If one wire is not in the correct spot.......
Pull the spark plug/s. See if it cranks/spins over the engine.
Were these new parts all OEM?
Thanks, Bertrrr. Could that be what's killing the battery voltage when I attach the trigger wire ? Even though I can jump the solenoid and start it ?You may want to pull the starter and bench test with 12volts , it should Jump and spin freely if not , bad starter,
Clamp it down good b/c it will Jump off the bench when you hook the voltage