QuestionQUESTION: Hi John
I think I have an electrical problem with my mower. 12.5 hp/40” Murray, B/S engine. Murray model #40631A, B/S Mod #286707/ purchased new 1992. Worked fine last weekend, now the engine won’t turn over; is completely dead when I turn the key. No clicking when I try to start it so assume solenoid OK. I did try jumping across the solenoid and the engine does crank & start. Spark plug is new and connected. Battery is new and I had it load tested when I purchased it a few days ago. Red cable connected tightly to positive post. New 15a fuse, and I had the clutch and PTO switch checked at a lawnmower repair shop; both tested OK. I checked the wiring harness and all of the wires are connected, don’t see any noticeable breaks. I cleaned the battery cables and posts. Adjusted the clutch to owner manual specs(it was loose)to make sure the clutch switch closes. Ignition switch functions normally; doesn’t feel any different than usual. I don’t have an ohmmeter; only a circuit tester which I presume won’t help me any. Only thing I can think of is a break in the wiring but have no idea how to check for that. Any ideas?
Thanks,
Don
ANSWER: Hello Don:
Have you Jumpered from the Positive Post of the Battery to the Small Post at the Base of the Starter Solenoid? What Happens, Please. If the Starter Engages, then Check the Current from the Ignition Switch to the Solenoid. Most Likely a Bad Wire or a Bad Safety Switch. I know you had them Checked, but I've had it Happen. Send me the Complete Model Numbers Off the Mower, Please. With these I can Locate the Proper Manual and Better Assist you. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.
Good Luck
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: John, thanks for the prompt response. I just tried jumping from the pos post to the solenoid; nothing happened but not sure I got a solid connection. The best thing I've got that will reach is a combination wrench unless you've got a better idea. If it cranks, what does that mean? I'll have to disassemble the mower to get back down to the ignition switch. I put it all back together before I contacted you. So that will be a couple of days before I can do that. And can I do that with a circuit tester or do I need an ohmmeter? How can a safety switch be bad if it tests OK(I'm completely lost when it comes to electrical components). I didn't find any additional model numbers for the mower, but here's some additional for the engine: Type: 0115 01; Code: 91121311.
Thanks, John
AnswerHello Don:
I Worded that Wrong. Sorry. Jumper from the Battery Terminal of the Solenoid to the Small Terminal in the Base of the Solenoid. If the Engine Turns, then the Solenoid is Good and the Ignition Switch is the Next Item to Check. If the Engine Does Not Turn, then the Solenoid is Bad. When Checking a Safety Switch I have Found that When Mounted they Move to the Same Point in Travel All the Time. When We Remove the Switch and Do a Test we Are Moving the Switch at a Different Point of Travel. It is Best to Check the Safety Switches while Mounted on the Equipment it is Designed to Function On. I think the Solenoid or the Switch May be the Cause. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.
Good Luck
Respectfully
John
