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Was: Noma(Murray) lawnmower won't start ...


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05-19-04, 06:46 AM   #1  
weasel
Noma (Murray) Lawn Tractor won't start.

Up until recently this ran like a gem. One day my wife was cutting the lawn and it just died. She thought it had run out of gas. It was low, so filler up ! Now for some reason, that wasn't it. It won't even turn over. I checked the fuse under the seat and its good. I bypassed all the safety switches and it still won't even turn. My lights won't even come on ! Its almost like someone stole my battery, but no, that's still there with lots of voltage. Is there anything else I should look at ? I will try to bypass the starter relay to see if I can get it to fire and then keep going, but the no headlight thing is weird ...

 
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05-19-04, 09:17 AM   #2  
Is your headlight supposed to come on automaticly when you turn the key on? I have never seen one like that. But if that is the setup than you are probably not getting voltage to the keyswitch. Use volt meter and test the wiring for 12 volts. It sounds like the Sylinoid has gone out. Let me know what you find. You will get more replies.

 
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05-19-04, 10:00 AM   #3  
Uh oh!

The head lights won't come on without the engine running, by design - they run off the alternator. But, back to your engine...How's the oil level? Sounds to me that you will find you have none when you check it. Let us know!!!

 
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05-19-04, 11:45 AM   #4  
weasel
No oil ??

Is there an oil level sender in these things ?? Anyway, got lots of oil. Right to the top of the hash marks, like it is supposed to be. About the headlights, I thought I remembered that they could run off the battery when the key was in run and the switch was on, but I could be wrong ..

Today, I bypassed all the safety switches and still nothing. Can't even hear the solenoid click. If you give that little terminal on the solenoid power, it will click like it supposed to and there is continuity across the terminals, but still no start. Starter doesn't even try. I gotta get this fixed soon or I am going to have to call a farmer to bail the lawn !

 
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05-19-04, 03:37 PM   #5  
Check for an inline fuse somewhere. My lawn tractor has a 30A fuse that, if blown, would cause a "no start problem". The fuse wouldn't explain why the engine quit though. The only thing that makes sense is a safety switch that opened for some reason. I've heard of engines with an oil level monitor that would shut the engine off if there's no oil. Perhaps that line is wired so the engine won't start as well. Without a wiring diagram it's hard to tell.

 
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05-19-04, 10:06 PM   #6  
Hello weasel!

You said you had continuity across the solenoid terminals. Did you check for power there as well? On the positive side? If you have continuity across the terminals, then the starter should have power regardless of safety switches, fuses, etc...

The battery cable goes straight to the solenoid post. If you have no voltage there, then the battery cable is bad, or the connections are bad, or the battery itself is bad.


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05-21-04, 05:00 AM   #7  
Test procedure

Do you have a test light? If not, a ohms meter? How many total wires go to the solenoid? Answer these and we'll continue.

 
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05-23-04, 01:38 PM   #8  
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Ya, I got a multimeter. Here is where I am right now. Key makes solenoid do nothing. If I jump power straight from the battery, solenoid works. I have battery power going to it and if I disconnect the power wire at the starter, I have power there, but none if its connected. I removed the starter and hooked it up to my cars battery. The wires try to weld themselves to the terminals, but it spins. I also checked for continuity between the positive terminal and the case. Read .4 ohms. That can't be good. Conclusion: short in the starter somewhere. Is there anyone who can tell me how to test it internally to verify this ? I used to know, but its been so long ...

Why the key does nothing, who knows. Maybe one of the bypasses for the safety switches isn't working so hot., but I checked all 4 and they seem to be fine.

 
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05-23-04, 11:10 PM   #9  
Does the solenoid click when you turn the key?


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05-24-04, 06:56 PM   #10  
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Mine is a Noma (Huskee)

I dont know about you but I would say not to let the wife use it. My wife used mine just last week and it would no longer start. I dont know what the heck she did but the starter gear was jammed against the flywheel. It would click but not start, so I pulled the starter cover off and there it was, jammed. Before I disconnected the switch cable from the starter, I loosened the bolts and pulled the starter back, turned the key and it spun just fine. The top washer was a bit mangled and there was this small cylindrical plastic piece just sitting on top of the starter gear. I have not figured out what the plastic piece is for yet.

Mine also has lights that turn on without the engine running. There are 2 running key positions. The first one will allow the lights to come on, even when it is not running and the second one will allow it to run without the lights.

Since yours seems similar, I know this is a stretch, but how do you engage the blades? Mine has a lever that pivots on the right side of the steering wheel and the handle crosses over to the left. That position is disengaged. The reason that I am asking is because I cant figure out how the blade brake linkage should be connected. Mine is not connected and I cant find out where it should go. The odds are against me but, how does your operate?

Chip

 
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05-25-04, 11:26 AM   #11  
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Sorry cheese, the solenoid doesn't click at all when I use the key, hence the reason I am so confused as to why this doesn't work correctly. THere has to be two things going on here ( or not going on to be correct ). One is the key will not activate the solenoid for some reason. Two, the starter will not go even if I jump the solenoid to make it go. The fuse is o.k. and wires appear to be alright as well.

Chip, my lever is on the left side beside the height adjustment. Your set-up sounds like my dad's. I think his is an MTD though ... anyway, the safety switch for his had broken from its mount many years ago, so we just reach down and depress the little button with our hands and then start it. A bit of a pain, but cheaper than a new switch !

 
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05-25-04, 03:43 PM   #12  
OK, from scratch now

First, remove the starter cable from the starter being sure to not let it touch metal. You never answered my question regarding the number of small guage wires at the solenoid, but I'll assume there's only one (if there's two, one is merely a grounding wire, because the solenoid may be mounted to something non-conductive). With your ohmeter, touch the meter probe to the small wire with the wire still attached to the solenoid, with someone seated on the mower and everything in neutral positions, have them turn the keyswitch to the start position. You should have a reading on your meter (doesn't much matter what the resistance is, just so long as you have power here). If not, and you are ABSOLUTELY certain that all safety switches are good, then you have a defective keyswitch. If you do have power here, on to the next step. Still with the starter cable removed, now check for continuity between the two heavy cable studs at the solenoid. Run your two test probes between each post (stud) on the solenoid. Have your assistant again turn the key to the start position. Continuity: good solenoid; No continuity: bad solenoid. If you have a good solenoid (and after reconnecting the starter cable to the starter), you still get no noise at the starter, then you have starter motor trouble. You have yet to indicate what you have for an engine, so we'll cross that bridge when the time comes, if needed.
BTW There is not a low oil shut-down on most lawn tractors, so this shouldn't be an issue.

 
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05-26-04, 12:40 AM   #13  
One quick thing to look for (it sounds like this may be the case): Pull the connector at the keyswitch and look at the keyswitch terminals. I bet one of them is badly corroded (the main power terminal). You can file the rust off and use it again if it isn't too bad.


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05-26-04, 09:26 AM   #14  
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Sorry cheese, I checked the wires there and all seem well.

puey61: Sorry about that. I have two small gauge wires going to it. The top one is a ground and the bottom is the one that would come from the key switch. Today I installed both my starter and my key switch in my Dad's lawnmower. His started up just fine. I would have checked for continuity ( in fact I tried ) between the two lugs at the solenoid, but I can't. The key won't activate it. If I run a wire straight from the battery to the little wire, I get continuity across the lugs. Hence the confusion here. The key will not trip the solenoid. I can, however, trip it running a wire straight to the battery. When I do this, I get continuity across the lugs, but the starter won't fire. The starter works rather well in my dad's mower. Somethings really wrong here and it's definately in the wiring. I just can't find the damned thing. I think I am going to try using my dad's key switch in my mower just to see what happens, although I doubt it will change anything.

BTW, I should have said much earlier, its a B&S 12hp

 
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05-27-04, 12:50 AM   #15  
I just noticed you said this after re-reading your past posts: "I have battery power going to it and if I disconnect the power wire at the starter, I have power there, but none if its connected. " Combine this statement along with : "Two, the starter will not go even if I jump the solenoid to make it go. The fuse is o.k. and wires appear to be alright as well." ....And since we know the starter is good, and the solenoid will work when power is applied to it manually, then...

This is a bad connection somewhere. It is showing a voltage at the wire with no-load, but as soon as you put it to a load, you lose it. That is classic of a bad connection. Look at where the cables connect to the battery. Are they corroded, rusty, green, frayed? Look where the negative cable connects to the frame too.


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05-27-04, 11:29 AM   #16  
It sounds like you have a large voltage drop when the starter is connected. That is, indeed, a classis sign of a bad connection, or of a bad solenoid. If the solenoid contacts are bad you could get a good voltage reading on the starter side of the solenoid when the solenoid is energized without the starter motor hooked up, but a reading close to zero when the starter is connected. When I see something like that happening I always suspect bad contacts inside the solenoid. The fact that the solenoid doesn't click when the key is turned may be a separate problem. That seems to be a clear cut case of an open switch somewhere in the safety circuit. The fact that the solenoid does click when jumpered dirctly from the battery positive terminal but still won't turn the starter motor, assuming a good starter, seems to point towards a bad solenoid or connection wire going to the starter itself. It sure looks like you are fighting two separate problems here. I suspect you will find that there is an open safety switch somewhere in the key switch circuit going to the solenoid AND a problem either with the solenoid itself or with the heavy leads coming into the solenoid from the battery, or going from the solenoid to the starter motor.

You can confirm if the problem is at the solenoid itself by making a simple test. Connect your voltmeter ACROSS the solenoid between the heavy wires, one coming from the battery, the other going to the starter. Without the solenoid being energized you should see about 12 volts, assuming a good battery. Now, energize the solenoid with your jumper wire going to the battery. When the solenoid clicks the starter motor should run and your voltmeter reading should drop to a reading close to zero. If the reading doesn't drop or reads something like 5 or 6 volts then your solenoid is, for sure, defective. The contacts are bad and you need a new solenoid.

A person could also do a quicker, but dirtier, test. Simply jumper across the heavy terminals on the solenoid itself with a HEAVY jumper wire, or a good pair of pliers with a heavy center pivot. Do is quickly and if your starter and wires to the starter motor are in good order the starter will crank. You don't even need to hold the short for a second to tell if the starter will crank. If you use a smaller wire and hold it in your hands be careful. The wire will get real HOT very QUICKLY, and you could get a nasty burn so you have to be careful.

 
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05-27-04, 12:43 PM   #17  
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I will do the test on the solenoid, but I think I may not have to. I may have discovered the problem. I pulled the wire harness out to have a look. I was checking for continuity and all seemed well. Wires were in good shape. Wondering why I kept getting no power to the solenoid, I checked it for continuity to ground. Sure enough there was. This would be the yellow wire that travels from the key through two safety switches and on to the solenoid. Keeping one probe to ground and the other on the wire, I removed the yellow wire from the solenoid and problem solved. So I check continuity between that little post and ground and guess what ? I guess that means I need a new solenoid. Assuming I am doing this right ...

 
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05-27-04, 02:52 PM   #18  
Little yellow wire

That yellow wire is the power wire, yes, from the key switch. Do you or do you not have power at this point - when you turn the key to the start position?

 
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05-27-04, 11:58 PM   #19  
Your post is a little confusing. You SHOULD have continuity between the small terminal and ground on your solenoid. An ohmmeter would probably read only a few ohms. At that point you should be reading the resistance of the solenoid coil. You should also see +12 volts there when the key is in the start position. If you don't see that then you still have a problem with either the key switch itself, or with an open safety switch. In an earlier post you said that you could take a jumper and connect it between the postive terminal of the battery and the small terminal of the solenoid and hear it click. That, to me, indicates that at least the coil part of the solenoid was working OK. What remains to be determined is if the heavy 12 volt circuit contacts inside the solenoid are in good order. That would keep the starter from turning even with the solenoid energized.

 
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05-28-04, 12:53 AM   #20  
This is getting very confusing. Too many contradictions. You said "If I run a wire straight from the battery to the little wire, I get continuity across the lugs. Hence the confusion here. The key will not trip the solenoid. I can, however, trip it running a wire straight to the battery. When I do this, I get continuity across the lugs, but the starter won't fire."

If you get continuity across the solenoid lugs when you apply power to activate the solenoid, then it is working. Yes, if the contacts in the solenoid are bad, it can cause the voltage drop...but so can bad connections elsewhere.

You will get continuity to ground on the yellow wire when it is connected to the solenoid. It is going to ground. It is just going through the coil in the solenoid before it gets to ground. That's what creates the electro-magnetic field that activates the solenoid. I see no reason to say the solenoid is positively bad yet.

Do this: While turning the key to start the engine, check the battery post on the solenoid for voltage (not the starter post). Is there 12v on it? If not, you have a bad connection elsewhere on the battery cables. The test Jughead gave you about jumping across the terminals is also a sure fire way to find out. If it won't start the engine that way, then you still have a bad connection on the battery cables.


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05-28-04, 03:21 AM   #21  
Go to your local OE dealer and buy a new key switch.

 
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05-28-04, 10:11 AM   #22  
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Whew, I thought that the coil was fried for a sec there. Guesss what ? Up until today, I had no power coming from the yellow wire at all. Suddenly today, I do ( I had verified that my key switch worked recently by installing it in my dad's mower ) Anyway, there must have been a bad connection somewhere because things seem to be working as advertised. No, I haven't gotten it to start yet, but I can trip the solenoid with the key and that's a big deal now. So, I will now hook up everything and see what happens, polishing ( not clean, but polish !! ) every connection along the way. I suspect that it might be the large amount of rust under the solenoid that was causing all the heartache. Will keep you posted !

Cheese, jughead: You're confused ?? I was just about ready to shoot it ! None of this made any sense and things should have worked when they didn't. We'll find out soon enough though ...

 
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05-28-04, 12:28 PM   #23  
Well, you did just say something that made a lot of sense when you said that there was a lot of rust under the solenoid. A lot of solenoids have one side of the coil connected to the solenoid frame internally. If there is a lot of rust around the solenoid mounting bracket the solenoid coil can't return to the negative side of the battery through the frame and won't energize. Hopefully everything else will work now when you get everything back together. You could still have other problems if your starter motor still won't run, but that should just be a connection problem between the battery and the solenoid, or between the solenoid and the starter motor. I suppose that the solenoid STILL could be defective, but a simple voltmeter check will tell you, as I've outlined in a previous post.

 
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05-28-04, 12:49 PM   #24  
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Back again. The key will now operate the solenoid, but as soon as I put a load on it, the solenoid no longer works ( with the key ). If I jump it from the battery, a few times, the key will work again ( as long as the starter isn't hooked up. ) I will be going out again to put a big set of pliers across the lugs to make sure the starter will go. I am confident it will as I could get it to run of my car's battery and it did work in my dad's mower. As a matter of fact, I'll go do that now ...

So much for that. Since I am running the wire on the outside of the mower, the starter wire isn't long enough to reach the starter. I tried using another piece of wire to make it longer. Guess I didn't have it well connected cause when I put the pliers across both lugs of the solenoid, no go. And now the key won't acivate the solenoid again, but I still have power going to it. Its gotta be that solenoid ....

 
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05-29-04, 02:36 AM   #25  
The solenoid is NOT bad if jumping across the terminals does not make the starter engage. You have a bad connection. No doubt.


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05-29-04, 08:23 AM   #26  
It does sound suspiciously like a bad connection somewhere. The tipoff is that it stops working when you put it under load. I'd say you are fighting two problems here. Problem one is on the coil side of the solenoid and problem two is on the switch side of the same solenoid. You must get the solenoid to click everytime the key is turned and you must be able to put a short across the heavy terminals and get the starter to turn in order to solve this problem. From your previous descriptions it really sounds like you have a couple of bad wires, switches, or terminal lugs somewhere.

One thought......How about checking for a GOOD ground on the negative side of your battery. I'm thinking that the negative side could be connected to a part of the machine that is in-turn connected to the chassis. If the ground isn't good all the way back to the chassis neither the starter or the solenoid would work properly. Perhaps the grounding problem could be at the battery itself. Have you taken the time to properly clean the battery terminals?? I've been making some assumptions that perhaps aren't valid. Loose mounting bolts between parts that are supposed to be tightly connected could cause some weird problems. Many people forget that the chassis itself and also some of the parts connected to the chassis may be part of the circuit just like any wire on the positive side. Loose, rusted, or corroded parts can and will cause you some real headaches if you forget that.

 
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06-10-04, 07:10 PM   #27  
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Was: Noma(Murray) lawnmower won't start ...

I can't find the old thread for some reason, but I had a recent success. I replaced the solenoid, discovered that with the new solenoid it makes a difference which wire goes where on the lugs. It tried to start, but no fire. I clipped one of the black wires coming from the ignition switch ( the one that goes to the safety's ) and it fired. It ran for a day and then suddenly wouldn't again.

Today I tested things again and found that I did have good battery voltage going to the solenoid ( instead of 9.5 on the other ) and I had good voltage to the little wire, yet it would not work. The only thing left was a better ground. I had thought that things were clean enough underneath the solenoid, but apparently not. I ran a wire from the nut that hold the solenoid on to the batterys ground and Voila !!!!!!!! Thanks for all the input guys, its really retarted when things check out like they are supposed to, but still don't work. Well it does now :-)

 
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06-10-04, 09:27 PM   #28  
Hi Weasel!

I found your old thread and merged the two together for you.


Glad you got it fixed! I knew you'd find a bad connection somewhere, lol. Sometimes electrical stuff can be a pain, especially when the problem is on the ground side of the circuit.


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