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Craftsman 917.273631 Fuses keeping blowing when blades are engaged


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09-16-09, 02:03 PM   #1  
Craftsman 917.273631 Fuses keeping blowing when blades are engaged

My mower just cut off the other day when cutting the grass. I have already changed the ignition switch and the solenoid. The mower runs just fine, then as soon as I engage the blades it runs for 3 seconds (blades never engage or turn) and dies. The ammeter shows -10 amps when running now so the battery is not charging either. Do I have some sort of short in the alternator or has it gone bad? Any help would be greatly appreciated.

 
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09-16-09, 03:11 PM   #2  
Your problem could be in the electric clutch, charging system, wiring or connections. I believe your clutch to be a Warner. You will find the Warner numbers on the back of the clutch. The link below tells how to test the clutch.

What is the engine model, etc. in the mower?

http://www.warnernet.com/litportal/p...8_P-1097-6.pdf

 
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09-19-09, 12:42 PM   #3  
Posted By: Airman Your problem could be in the electric clutch, charging system, wiring or connections. I believe your clutch to be a Warner. You will find the Warner numbers on the back of the clutch. The link below tells how to test the clutch.

What is the engine model, etc. in the mower?

http://www.warnernet.com/litportal/p...8_P-1097-6.pdf
The engine is a Briggs and Stratton 18.5 Intek Plus OHV. The clutch is a Warner 5217-9. I got the clutch off and will test per your guidance.

Another question, would a bad clutch affect the battery charging? I wouldn't think so, but I really don't know. The ammeter shows negative with the lawn mover on, off, battery hot disconnected, etc. It moves slightly when I engage the blades then the fuse blows.

Thanks again for any assistance.

 
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09-19-09, 01:42 PM   #4  
The clutch will not affect battery charging. I will look at your charging system tomorrow and post back.

 
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09-19-09, 02:47 PM   #5  
Posted By: Airman The clutch will not affect battery charging. I will look at your charging system tomorrow and post back.
Well, I tested the clutch and could not get the multimeter to register any reading, it just stayed on "1". I tested it on some other items and got readings just to be sure the multimeter was working properly, but when I put it on the clutch it didn't just stayed on "1" - no reading. Also, it looks to be some melted plastic under the clutch connector plug, don't know for sure but it's either melting or some sort of shredding from usage.

The ammeter has been reading negative for a month or so now and I also believe the battery is not being charged as well.

Looking forward to hearing something as you mentioned....thanks again.

 
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09-19-09, 08:45 PM   #6  
Do you have to jump start it?


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09-20-09, 04:33 AM   #7  
Posted By: cheese Do you have to jump start it?
Not yet, but if it was still running (mowing) I believe I would. I took the opportunity to charge the battery and I can definitely tell the difference when cranking.

I believe I had a preexisting issue, the failing or failed alternator as well as the new clutch problem, maybe.

 
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09-20-09, 06:39 AM   #8  
Clarify these items:
You said, “My mower just cut off the other day when cutting the grass.” Does this mean the mowers blades stopped turning or did the engine shutoff?

You said, “I have already changed the ignition switch and the solenoid.” Was this done in an attempt to correct problem above?

You said, “The mower runs just fine, then as soon as I engage the blades it runs for 3 seconds (blades never engage or turn) and dies.” I understand this to mean the engine starts and runs good. When PTO clutch is engaged engine dies, correct?

You said, “It moves slightly when I engage the blades then the fuse blows.” What moves slightly? Did the fuse blow when the problem first started or did this begin later?

Also, check your Private Messages.

 
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09-20-09, 01:33 PM   #9  
Airman's clarifications

Clarify these items:
You said, “My mower just cut off the other day when cutting the grass.” Does this mean the mowers blades stopped turning or did the engine shutoff? The engine just shutdown while I was mowing.
You said, “I have already changed the ignition switch and the solenoid.” Was this done in an attempt to correct problem above? Yes, I thought the switch and/or the solenoid was the source of the blown fuses. These items are brand new.

You said, “The mower runs just fine, then as soon as I engage the blades it runs for 3 seconds (blades never engage or turn) and dies.” I understand this to mean the engine starts and runs good. When PTO clutch is engaged engine dies, correct? Yes sir, the mower runs just great until I push in the PTO button. Once the button is pressed, the blades never spin and the fuse blows about three seconds later. But when I disconnect the clutch from the wiring harness and press the pto button the engine doesn't die (no load to the clutch)
You said, “It moves slightly when I engage the blades then the fuse blows.” What moves slightly? Did the fuse blow when the problem first started or did this begin later? The needle on the ammeter moves slightly, a wiggle in the negative direction, then the fuse blows. I never had a blown fuse issue until the mower died in the field the other day. Since then, the fuses have been blowing everytime I try to engage the blades. The blades never move or rotate. I believe I had a bad alternator for awhile as the ammeter has been negative the last few mowings. Before the fuse issue, I had to really hold the key over and the battery strained to crank the mower. I had the battery on a charger and it fires right up now, just no blade engagement.

 
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09-20-09, 05:24 PM   #10  
I suspect you have a short in the wiring to the clutch. Check harness Key No. 80 for shorts. Also check for a short in the two wires of the main harness that go back to the PTO and ignition switch.

Look at the clutch’s connector and wiring closely for a break (open circuit). Apparently, something melted and created a break in the wire or connector. These clutches are not cheap. You can straight wire the clutch if needed using pigtail connectors if necessary.

Key numbers, etc are in this Owners manual:
http://www.managemyhome.com/mmh/lis_...M/L0407112.pdf

 
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09-21-09, 06:26 AM   #11  
Key No. 80 connector looks great, no nicks, cuts, etc. Connectors at both ends look great.

However, in the connector on the tractor harness that connects to 80 is a small bare wire the jumps over from the red wire connector to the black wire connector. Looks like it was made that way, and the little bare wire just goes into the sleeve around the red wire and ends there. Not sure what that's for but it looks made that way. Thought I'd mention.

Had the clutch retested, still no ohms reading just "1". The bottom of the connector on the clutch between the actual connector and the clutch body looks to be melted slightly or slightly shredded, almost like caulking. Pulley turns freely by hand both ways, though it is a little tight (not free-spinning) but it's not locked up.

 
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09-21-09, 07:40 AM   #12  
I just sent pcjames4 an email before I read his latest post.

My email read, "Disconnect the short harness that connects the clutch wiring to the tractor wiring harness. You can see the diode in the wiring and it may be burned. If it doesn't look shorted you will need to test it. To properly test it you need a meter with a diode checker in it. If it is shorted you will need to replace the clutch harness and the PTO switch. The part number for the clutch harness is 146685. Local small engine dealers should have this part or you can get it through sears or online.

Check all wiring in the circuit closely for worn spots or shorts."

After his latest post I will offer this:
A reading of "1" indicates an open circuit which will not blow a fuse.

Try this, pierce each clutch wire past the connector, closer to the clutch, with a safety pin and take a reading. If you get resistance then the break “open” is between that point and the connector. If it still shows open something internal to the clutch apparently burned through and will require a new clutch. But something is still shorting so do not install a new clutch.

I will read and digest your latest post and get back to you.

 
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09-21-09, 02:08 PM   #13  
Here are steps that may clear up any confusion:

I suspect a short in the wiring between PTO switch and clutch is cause the problem. I suspect the engine is shutting off because when PTO switch is engaged the ignition circuit is grounded.

Test clutch with PN 146685 small harness disconnected. Test clutch per Warner manual referenced earlier.

The open circuit reading on the clutch could mean the clutch internal wiring burned through, due to short, creating an open circuit.

With small harness removed, test diode in small harness.

Test wires, to locate short, in main harness from the end that plugs into small harness to PTO connector. NOTE: Only disturb ends of harness. The short may be inside harness and moving harness may make it impossible to find short.

I left the testing the PTO switch out. I do not think it is the problem.

 
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09-21-09, 08:00 PM   #14  
I'd unplug the pto clutch and then crank up the mower and turn on the pto switch. If the fuse does not blow, you have isolated the problem to the clutch itself.

The fact that you show only 1 ohm of resistance in the coil tells me the windings are shorted to themselves and possibly the case. Check ohms from a clutch terminal to the outer case. If you get any reading at all other than out of limits, then it is shorted there as well. You typically want to see 2.5 to 5 ohms in a clutch coil winding that is not shorted. 1 ohm indicates the windings are not insulated from each other anymore and it is shorted internally.


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09-22-09, 06:35 AM   #15  
Cheese,
I understand pcjames4 as saying the digital multimeter is not reading 1 ohm but is not changing from the reading of 1, which indicates an open circuit. Earlier pcjames4 said, “Had the clutch retested, still no ohms reading just "1".

If the clutch in fact has an open circuit there was an internal break in the winding that I have never seen but I guess is possible.

I have a suspicion the problem originated in the small harness that contains the diode. He saw melting in that area and it is a common source of shorts from my experience. However, when a short has occurred and electrical damage done it is best to check the complete system.

Cheese, good call on disconnecting the PTO clutch to check the PTO switch for shorts. Disconnecting the clutch from the circuit will tell you if there is a short just not where but that can be determined in other ways.

Several years back I went to an AYP/Frigidaire troubleshooting school. When AYP began installing the various operator presence systems, they use things got complicated. Training focused on troubleshooting using the AYP Diagnosis Kit. I purchased their diagnostic kits and they have paid for themselves many times. Using the jumper portion kit and other diagnosis tools, I can quickly find a problem.

 
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09-22-09, 01:08 PM   #16  
Fuses keeps blowing

Well folks, just got finished doing all the testing.

- I cranked the mower with the clutch connected to the harness. engaged the PTO and of course the fuse blew.

- I then cranked the mower without the clutch connected to the harness, engaged the PTO and the mower continued to run.

- Then I removed both the clutch and the harness (just part 80 clutch connector) and took to the parts to store to have the "I&E" guy test with multimeter. He tested the harness, first at each connection and then from end to end and said it was fine. He tested the clutch and got the same "1" reading I got, the meter stayed on "1". He then mumbled some electrical jargon that I have no clue about and said the clutch is toast.

What are your thoughts? Also, what about the fact that the mower does not appear to be charging? Could I have been bitten by two separate gremlins or is the clutch and apparent alternator issue related?

I REALLY appreciated all of the help I have been getting.

 
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09-22-09, 02:33 PM   #17  
I would bet on your clutch being the problem as well.
Measure the DC voltage on your battery with the key and engine "off"
Then while the engine is running full throttle.

If you have a good charged battery, static should be 12.5 to 13V DC. If you read over 13 V DC preferably 13.5 to 14.5 VDC with the engine running then it is charging.

Even with those good readings it is possible to have other shorts but they may be negligible or intermittent.

 
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09-22-09, 03:57 PM   #18  
I agree that the clutch is bad. As I mentioned in an earlier post, a reading of 1 ohm in the clutch windings is a shorted coil regardless of the condition of the diode. An open winding would show as OL or open on a digital multimeter, and all the way pegged out on an analog meter. I see broken windings in these coils often when the coil epoxy comes loose from the housing which allows the coil to scrub the turning clutch disk and wear into it, or pull loose from the wires where they go through the housing to the connector.

I like to see more than 13 volts at the battery with a good battery and the engine running full throttle.

Edit: I have since seen that some multimeters show 1 ohm when there is actually an open circuit. Why they would show a closed circuit reading for an open circuit situation is beyond me, but I don't make the things. If your meter is this way, it could be a different problem as Airman suggests. What does your meter show for open circuits?


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Last edited by cheese; 09-23-09 at 10:07 PM.
 
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09-23-09, 10:07 PM   #19  
Bump to top, edited previous post.


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09-24-09, 05:07 AM   #20  
Posted By: cheese I agree that the clutch is bad. As I mentioned in an earlier post, a reading of 1 ohm in the clutch windings is a shorted coil regardless of the condition of the diode. An open winding would show as OL or open on a digital multimeter, and all the way pegged out on an analog meter. I see broken windings in these coils often when the coil epoxy comes loose from the housing which allows the coil to scrub the turning clutch disk and wear into it, or pull loose from the wires where they go through the housing to the connector.

I like to see more than 13 volts at the battery with a good battery and the engine running full throttle.

Edit: I have since seen that some multimeters show 1 ohm when there is actually an open circuit. Why they would show a closed circuit reading for an open circuit situation is beyond me, but I don't make the things. If your meter is this way, it could be a different problem as Airman suggests. What does your meter show for open circuits?
It shows "1" for open circuits.

 
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09-24-09, 07:33 PM   #21  
Wow, apparently this is a common enough setup for some multimeters. Mine (fluke) shows OL, and I don't remember what my other one shows for an open circuit.

What does your meter show from each terminal of the clutch to the case of the clutch?


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09-25-09, 01:44 AM   #22  
Posted By: cheese Wow, apparently this is a common enough setup for some multimeters. Mine (fluke) shows OL, and I don't remember what my other one shows for an open circuit.

What does your meter show from each terminal of the clutch to the case of the clutch?
It shows "1", it never registers any other reading when the clutch is tested.

 
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09-25-09, 05:59 PM   #23  
So then if your meter is accurate in showing 1 ohm in place of an open circuit, then the coil windings are broken and the clutch is bad internally, but this would not blow the fuse. If your meter is showing 1 ohm, literally meaning 1 ohm, from one terminal to the other, then the coil windings are shorted internally and this would blow the fuse. Still sounds to me like you have a bad clutch.


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09-25-09, 06:33 PM   #24  
What does your meter read when checking the battery voltage as described?

 
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09-26-09, 11:54 AM   #25  
Posted By: BFHFixit What does your meter read when checking the battery voltage as described?
12.7 V full throttle at the battery.....having to really hold the key over to start...ammeter showing negative all the time.

 
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09-26-09, 12:58 PM   #26  
Disconnect the alternator and test it per the manual. Those amp gauges on mowers are not reliable. I suspect if you do have a damaged alternator it originated from the clutch problem, unless voltage has been improperly applied when jumping, etc.

Although the clutch connectors tested as having an open circuit I think you will find a short when testing between an individual connector on the clutch and the clutch case. Have you done this? It takes a short to blow a fuse. That short is either in the clutch or wiring.

Did you install the short harness (not connected to clutch) and see if engine shuts off?

The problem as I understand is the fuse blows and the engine shuts off.

Here is what I think may be happening:

When engaging the PTO the fuse blows due to short in clutch. The engine shuts down because when fuse blew voltage is removed from the carburetor fuel shut-off solenoid shutting off fuel. This can be verified by a voltage test of the fuel shut-off solenoid. Does the engine have a fuel shut-off solenoid?

FYI: The ignition coil does not operate off electricity so there is no correlation to alternator.

I am guessing the problem is the coil shorted to case. Coil tests as open and it would not work with an open condition and would not blow fuses.

 
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09-26-09, 01:24 PM   #27  
VAROOOOMMMM!!!!!!!

That sound you hear coming from Houston is my lawnmower and its new clutch NOT blowing fuses. So many thanks to Airman, Cheese, BFHFixit for all the help.

I haven't put the deck back under it yet so I don't know how it cuts, but I can see the new clutch engaging and spinning without blowing the fuse.

Airman: I could not access that alternator testing link but I will try again. Heck, I don't even know where the alternator is located or how to access it.

 
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09-26-09, 01:30 PM   #28  
Glad you have it fixed. It is always best to determine which part is bad before you throw money at it.

If you need help post back.

 
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09-26-09, 01:42 PM   #29  
Posted By: Airman Glad you have it fixed. It is always best to determine which part is bad before you throw money at it.

If you need help post back.
I do, alternator testing method.

 
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09-26-09, 03:09 PM   #30  
Posted By: pcjames4 12.7 V full throttle at the battery.....having to really hold the key over to start...ammeter showing negative all the time.
What does the battery read with the engine off and the key in the off position?

This is a way to find out if your alternator is charging. 12.7 V at full throttle is a bit low. You could still have a short in a switch or wiring.
However if your battery reads 12.7V with the engine off then your alternator is not charging and can be diagnosed further.

I think Airman is shooting you a PM so....

 
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09-26-09, 04:51 PM   #31  
Posted By: BFHFixit What does the battery read with the engine off and the key in the off position?

This is a way to find out if your alternator is charging. 12.7 V at full throttle is a bit low. You could still have a short in a switch or wiring.
However if your battery reads 12.7V with the engine off then your alternator is not charging and can be diagnosed further.

I think Airman is shooting you a PM so....
Reading 12.56 V with engine off and key in the off position.......I have a brand new switch, solenoid, and clutch.

I'll wait to hear something about the alternator testing.....

 
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09-26-09, 09:56 PM   #32  
The alternator has two wires coming out to one connector. If both wires are the same color, they go to a regulator. If they are red and black, test for DC voltage with the red lead of the meter on the red wire at the connector, and the black lead of the meter grounded to the engine block, with the engine running full speed. If you have less than 13 volts, check for AC voltage in the same place. If you have none, check for AC voltage above in the red wire above the black shrink wrapped diode near the connector. If you have AC voltage there (probably 25-30 volts if I recall correctly), then the diode is bad. If you have little or no AC voltage there, the charging stator is bad.

If yours has a regulator, check for AC voltage with one meter lead in one connector from the stator, and the other in the other, and you should have no less than 20 VAC with the engine full rpm. Less than 20 is a bad stator. 20 or more, then check for DC on the red wire from the regulator with the engine full rpm and the stator plugged back in. If there is less than 13 volts, the regulator is bad. If 13 volts or more, the charging system is working and you have a bad connection elsewhere.


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