Started right up after winter storage. Constant smart battery charging always showing 100%, 12.7 v. But when brake pedal was released, engine stopped. Craftsman schematic shows mechanical grounding switches used to kill magneto. The seat and PTO switch were removed and buzzed out ok including a stress test (haha) of the PTO contacts (in vise , wiggle blades). Again no fault found with buzz out. Prepared for deeper look with a battery charge....Smart charger screen said to connect clamps...they were already in place. So apparently my smart battery charger (Viking and EverStart) will not recognize a battery with only 2 v. on the terminals. Checked with VOM...sure enough , only 2.1 v. A hydrometer test showed low electrolyte reading. Apparently the cranking to start (load test) had revealed a failed battery. The PTO switch terminals were lightly coated with bulb grease and repeatedly inserted and withdrawn from the mating female (dash) connector in an attempt to improve contacts. Then it and the seat switch installed. A used battery was installed, itself only fair electrolyte. EUREKA ! The engine booms to life and the brake pedal problem is gone. The failed battery must have had a surface charge. But is the magneto kill associated with voltage? The schematic of the PTO switch shows contact A should not touch contact D. If it does it looks like grounding is available through D to the magneto, stopping engine. Did the bulb grease exercise temporarily help? A buzz out can not simulate an operating current. There are many PTO switch sales on ebay, whether changed out by guess or by golly. I may have to replace it. Your thoughts ?
DYT 4000 Electrical Gremlins
- Thread starter motoman
- Start date
Started right up after winter storage. Constant smart battery charging always showing 100%, 12.7 v. But when brake pedal was released, engine stopped. Craftsman schematic shows mechanical grounding switches used to kill magneto. The seat and PTO switch were removed and buzzed out ok including a stress test (haha) of the PTO contacts (in vise , wiggle blades). Again no fault found with buzz out. Prepared for deeper look with a battery charge....Smart charger screen said to connect clamps...they were already in place. So apparently my smart battery charger (Viking and EverStart) will not recognize a battery with only 2 v. on the terminals. Checked with VOM...sure enough , only 2.1 v. A hydrometer test showed low electrolyte reading. Apparently the cranking to start (load test) had revealed a failed battery. The PTO switch terminals were lightly coated with bulb grease and repeatedly inserted and withdrawn from the mating female (dash) connector in an attempt to improve contacts. Then it and the seat switch installed. A used battery was installed, itself only fair electrolyte. EUREKA ! The engine booms to life and the brake pedal problem is gone. The failed battery must have had a surface charge. But is the magneto kill associated with voltage? The schematic of the PTO switch shows contact A should not touch contact D with PTO off. If it does it looks like grounding is available through D to the magneto, stopping engine. Did the bulb grease exercise temporarily help? A buzz out can not simulate an operating current. There are many PTO switch sales on ebay, whether changed out by guess or by golly. I may have to replace it. Your thoughts ?
The brake lever stopped the engine when released. A bad battery was found. Nothing else was replaced. Was the problem solved by replacing the battery, jiggling the old PTO switch, or divine intervention....an immaculate connection? Buzz out is multimeter ohm setting that beeps when contact is between the two test probes, so it is a beep out.
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"immaculate connection"
I like that!
I like that!
Started teaching electricity in the early 80’s using a Simpson 262 VOM analog meter and today my go to meter is a Fluke 179. This is the first time I’ve ever heard that term. Learn something new everyday.
Rivets, In a former life I worked in electronics . The term buzz out is very common there. I can report that the tractor is running well, including PTO. I have never liked not knowing reasons for problems (a frustrating trait) , especially when they seem to cure themselves. So I am still puzzled why the magneto kill wiring cured itself since the schematic does not show that voltage is a factor ( a replacement battery). That is why I suggested the PTO switch contact could play a role. Inside that switch are some contacts which might be affected by sparking, and deposits from age and moisture. A youtuber cut a switch open and the contacts are in close proximity so bridging can occur (shorting). Some circumstantial evidence also in the high volume of PTO switch sales shown on line (if you can believe it). Meanwhile I will just thank the gods .
BTW Rivets, I have always chuckled at your mantra as teacher. But you break the mold, defying the old adage ... those who can do.....those who cannot, teach. I think you can....do!
BTW Rivets, I have always chuckled at your mantra as teacher. But you break the mold, defying the old adage ... those who can do.....those who cannot, teach. I think you can....do!
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I try, but always say “the day I stop learning I’ll no longer be vertical “. I’ve probably worked with too many old farts. 90% of the teachers get a bad rap, just like an profession, I’ve worked with many of the 10%ers.