QuestionQUESTION: I have a Stx38(yellow Deck) It suddenly stopped charging. I checked voltage on the regulator with engine running and have approximately 38 Vac to ground on the left terminal/no 12 volts on center terminal I suspect this is a problem from what I have read)/nothing on right terminal. My problem is I'm having a problem tracing the voltage to see where I lose it.(no schematic).
Thanks
Larry
ANSWER: To check the charging system you need to test for AC voltage between the 2 outside terminals on the regulator. You should have 30+. If not 30+ you need a new stator. If you have 30AC+ check the center terminal to ground for DC voltage you should have about 13.5. If you don't check the regulator ground. If the ground is good, replace the reg/rect. If the ground is bad repair and retest.
You should always have battery voltage atleast at the center terminal with the key on. If not you need to trace the power wire to the battery. The week point is the circuit breaker bolted into the back of the battery box.
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QUESTION: Hi,
First of all thank you for your service, and sharing your knowledge.
On the stx38 charging system question, my 25 amp breaker checked fine. I suspected the ignition switch after this, so I bought a new one. Didn't work, still no voltage to the center terminal of the regulator. Then I got mad and decided to do some serious trouble shooting. I removed the battery and put my lead on the positive terminal, started going back. Through the breaker/ to ignition switch/ and since my pto clutch worked fine I never suspected the switch for it. The wire looped and went through the pto switch and at this point I lost it. I took the pto switch off and sprayed wd40 down inside it and worked it several times. Checked continuity and YES!
Put battery back in and checked voltage on center terminal and YES. So basically I came out cheap compared to what it could have cost me. ie $16.95 for the ignition switch, and I still have a spare. BTW this is a good tractor the yellow deck belt is a little difficult to change but I can do it in about 40 minutes. MY suggestion is never buy a cheap belt for it. lol (learned the hard way).
Just thought I would share this with you and you can paste this to your readers if you desire.
Thanks again
Larry
AnswerI commend you on exerting the effort required to fix the tractor.
I can tell you this though, the power circuit going to the center of the regulator never passes though the PTO switch. I have a new tech that did the same thing this past week. What he really did was test the breaker, this plug system is very prone to corrosion. since the breaker posts are threaded when he tested the breaker he moved the plug and the threads on the breaker wiped the corrosion off. Either way, you got the old girl going again. The deck belt is easy to change. getting the deck off is the hard part.
